Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Sec24C is an HIV-1 host dependency factor crucial for virus replication

Abstract

Early events of the human immunodeficiency virus 1 (HIV-1) lifecycle, such as post-entry virus trafficking, uncoating and nuclear import, are poorly characterized because of limited understanding of virus–host interactions. Here, we used mass spectrometry-based proteomics to delineate cellular binding partners of curved HIV-1 capsid lattices and identified Sec24C as an HIV-1 host dependency factor. Gene deletion and complementation in Jurkat cells revealed that Sec24C facilitates infection and markedly enhances HIV-1 spreading infection. Downregulation of Sec24C in HeLa cells substantially reduced HIV-1 core stability and adversely affected reverse transcription, nuclear import and infectivity. Live-cell microscopy showed that Sec24C co-trafficked with HIV-1 cores in the cytoplasm during virus ingress. Biochemical assays demonstrated that Sec24C directly and specifically interacted with hexameric capsid lattices. A 2.3-Å resolution crystal structure of Sec24C228–242 in the complex with a capsid hexamer revealed that the Sec24C FG-motif bound to a pocket comprised of two adjoining capsid subunits. Combined with previous data1,2,3,4, our findings indicate that a capsid-binding FG-motif is conserved in unrelated proteins present in the cytoplasm (Sec24C), the nuclear pore (Nup153; refs. 3,4) and the nucleus (CPSF6; refs. 1,2). We propose that these virus–host interactions during HIV-1 trafficking across different cellular compartments are crucial for productive infection of target cells.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Identification of Sec24C as a cellular interacting partner of HIV-1 cores.
Fig. 2: A role of Sec24C during early steps of HIV-1 infection.
Fig. 3: A role of Sec24C in spreading of replication-competent HIV-1 in Jurkat cells.
Fig. 4: Structural basis for Sec24C228–242 interaction with the CA hexamer.

Similar content being viewed by others

Data availability

The datasets generated and analysed during the current study are included in this article or are available in the Protein Data Bank under the accession number 6PU1 (structural data) and via ProteomeXchange with identifier PXD020970 (proteomics data). All other data are available from the corresponding author upon request. Source data are provided with this paper.

References

  1. Price, A. J. et al. CPSF6 defines a conserved capsid interface that modulates HIV-1 replication. PLoS Pathog. 8, e1002896 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Lee, K. et al. Flexible use of nuclear import pathways by HIV-1. Cell Host Microbe 7, 221–233 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Matreyek, K. A., Yucel, S. S., Li, X. & Engelman, A. Nucleoporin NUP153 phenylalanine-glycine motifs engage a common binding pocket within the HIV-1 capsid protein to mediate lentiviral infectivity. PLoS Pathog. 9, e1003693 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  4. Price, A. J. et al. Host cofactors and pharmacologic ligands share an essential interface in HIV-1 capsid that is lost upon disassembly. PLoS Pathog. 10, e1004459 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  5. Rasaiyaah, J. et al. HIV-1 evades innate immune recognition through specific cofactor recruitment. Nature 503, 402–405 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Campbell, E. M. & Hope, T. J. HIV-1 capsid: the multifaceted key player in HIV-1 infection. Nat. Rev. Microbiol. 13, 471–483 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Yamashita, M. & Engelman, A. N. Capsid-dependent host factors in HIV-1 infection. Trends Microbiol. 25, 741–755 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Mattei, S., Glass, B., Hagen, W. J., Krausslich, H. G. & Briggs, J. A. The structure and flexibility of conical HIV-1 capsids determined within intact virions. Science 354, 1434–1437 (2016).

    Article  CAS  PubMed  Google Scholar 

  9. Zhao, G. et al. Mature HIV-1 capsid structure by cryo-electron microscopy and all-atom molecular dynamics. Nature 497, 643–646 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Brass, A. L. et al. Identification of host proteins required for HIV infection through a functional genomic screen. Science 319, 921–926 (2008).

    Article  CAS  PubMed  Google Scholar 

  11. Franke, E. K., Yuan, H. E. & Luban, J. Specific incorporation of cyclophilin A into HIV-1 virions. Nature 372, 359–362 (1994).

    Article  CAS  PubMed  Google Scholar 

  12. Thali, M. et al. Functional association of cyclophilin A with HIV-1 virions. Nature 372, 363–365 (1994).

    Article  CAS  PubMed  Google Scholar 

  13. Goujon, C. et al. Human MX2 is an interferon-induced post-entry inhibitor of HIV-1 infection. Nature 502, 559–562 (2013).

    Article  CAS  PubMed  Google Scholar 

  14. Kane, M. et al. MX2 is an interferon-induced inhibitor of HIV-1 infection. Nature 502, 563–566 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Bulli, L. et al. Complex interplay between HIV-1 capsid and MX2-independent alpha interferon-induced antiviral factors. J. Virol. 90, 7469–7480 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Kane, M. et al. Nuclear pore heterogeneity influences HIV-1 infection and the antiviral activity of MX2. eLife 7, e35738 (2018).

  17. Jensen, D. & Schekman, R. COPII-mediated vesicle formation at a glance. J. Cell Sci. 124, 1–4 (2011).

    Article  CAS  PubMed  Google Scholar 

  18. Enninga, J., Levay, A. & Fontoura, B. M. Sec13 shuttles between the nucleus and the cytoplasm and stably interacts with Nup96 at the nuclear pore complex. Mol. Cell. Biol. 23, 7271–7284 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Mancias, J. D. & Goldberg, J. Structural basis of cargo membrane protein discrimination by the human COPII coat machinery. EMBO J. 27, 2918–2928 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Lee, K. et al. HIV-1 capsid-targeting domain of cleavage and polyadenylation specificity factor 6. J. Virol. 86, 3851–3860 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Gamble, T. R. et al. Crystal structure of human cyclophilin A bound to the amino-terminal domain of HIV-1 capsid. Cell 87, 1285–1294 (1996).

    Article  CAS  PubMed  Google Scholar 

  22. Stremlau, M., Perron, M., Welikala, S. & Sodroski, J. Species-specific variation in the B30.2(SPRY) domain of TRIM5alpha determines the potency of human immunodeficiency virus restriction. J. Virol. 79, 3139–3145 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Robinson, S. B. et al. Sequence determinants of the Caenhorhabditis elegans dopamine transporter dictating in vivo axonal export and synaptic localization. Mol. Cell Neurosci. 78, 41–51 (2017).

    Article  CAS  PubMed  Google Scholar 

  24. Bajaj Pahuja, K. et al. Phosphoregulatory protein 14-3-3 facilitates SAC1 transport from the endoplasmic reticulum. Proc. Natl Acad. Sci. USA 112, E3199–E3206 (2015).

    Article  PubMed  CAS  PubMed Central  Google Scholar 

  25. Ehrlich, L. S., Agresta, B. E. & Carter, C. A. Assembly of recombinant human immunodeficiency virus type 1 capsid protein in vitro. J. Virol. 66, 4874–4883 (1992).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Shah, V. B. & Aiken, C. In vitro uncoating of HIV-1 cores. J. Vis. Exp. 57, e3384 (2011).

  27. Francis, A. C., Marin, M., Shi, J., Aiken, C. & Melikyan, G. B. Time-resolved imaging of single HIV-1 uncoating in vitro and in living cells. PLoS Pathog. 12, e1005709 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  28. Francis, A. C. & Melikyan, G. B. Single HIV-1 imaging reveals progression of infection through CA-dependent steps of docking at the nuclear pore, uncoating, and nuclear transport. Cell Host Microbe 23, 536–548 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Dalgleish, A. G. et al. The CD4 (T4) antigen is an essential component of the receptor for the AIDS retrovirus. Nature 312, 763–767 (1984).

    Article  CAS  PubMed  Google Scholar 

  30. Klatzmann, D. et al. T-lymphocyte T4 molecule behaves as the receptor for human retrovirus LAV. Nature 312, 767–768 (1984).

    Article  CAS  PubMed  Google Scholar 

  31. Peng, K. et al. Quantitative microscopy of functional HIV post-entry complexes reveals association of replication with the viral capsid. eLife 3, e04114 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  32. Blair, W. S. et al. HIV capsid is a tractable target for small molecule therapeutic intervention. PLoS Pathog. 6, e1001220 (2010).

  33. Shi, J., Zhou, J., Shah, V. B., Aiken, C. & Whitby, K. Small-molecule inhibition of human immunodeficiency virus type 1 infection by virus capsid destabilization. J. Virol. 85, 542–549 (2011).

    Article  CAS  PubMed  Google Scholar 

  34. Bester, S. M. et al. Structural and mechanistic bases for a potent HIV-1 capsid inhibitor. Science 370, 360–364 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Link, J. O. et al. Clinical targeting of HIV capsid protein with a long-acting small molecule. Nature 584, 614–618 (2020).

  36. Adachi, A. et al. Production of acquired immunodeficiency syndrome-associated retrovirus in human and nonhuman cells transfected with an infectious molecular clone. J. Virol. 59, 284–291 (1986).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Connor, R. I., Chen, B. K., Choe, S. & Landau, N. R. Vpr is required for efficient replication of human immunodeficiency virus type-1 in mononuclear phagocytes. Virology 206, 935–944 (1995).

    Article  CAS  PubMed  Google Scholar 

  38. Kirmaier, A. et al. TRIM5 suppresses cross-species transmission of a primate immunodeficiency virus and selects for emergence of resistant variants in the new species. PLoS Biol. 8, e1000462 (2010).

  39. Akiyama, H. et al. HIV-1 intron-containing RNA expression induces innate immune activation and T cell dysfunction. Nat. Commun. 9, 3450 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  40. Saenz, D. T., Barraza, R., Loewen, N., Teo, W. & Poeschla, E. M. Feline immunodeficiency virus-based lentiviral vectors. Cold Spring Harb. Protoc. 2012, 71–76 (2012).

    PubMed  Google Scholar 

  41. Olsen, J. C. Gene transfer vectors derived from equine infectious anemia virus. Gene Ther. 5, 1481–1487 (1998).

    Article  CAS  PubMed  Google Scholar 

  42. Saenz, D. T., Teo, W., Olsen, J. C. & Poeschla, E. M. Restriction of feline immunodeficiency virus by Ref1, Lv1, and primate TRIM5alpha proteins. J. Virol. 79, 15175–15188 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Soneoka, Y. et al. A transient three-plasmid expression system for the production of high titer retroviral vectors. Nucleic Acids Res. 23, 628–633 (1995).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Naldini, L. et al. In vivo gene delivery and stable transduction of nondividing cells by a lentiviral vector. Science 272, 263–267 (1996).

    Article  CAS  PubMed  Google Scholar 

  45. Morrison, J. H. et al. Feline immunodeficiency virus envelope glycoproteins antagonize tetherin through a distinctive mechanism that requires virion incorporation. J. Virol. 88, 3255–3272 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  46. Stremlau, M. et al. The cytoplasmic body component TRIM5alpha restricts HIV-1 infection in Old World monkeys. Nature 427, 848–853 (2004).

    Article  CAS  PubMed  Google Scholar 

  47. de Chaumont, F. et al. Icy: an open bioimage informatics platform for extended reproducible research. Nat. Methods 9, 690–696 (2012).

    Article  PubMed  CAS  Google Scholar 

  48. Janas, A. M. & Wu, L. HIV-1 interactions with cells: from viral binding to cell–cell transmission. Curr. Protoc. Cell Biol. 43, 26.5.1–26.5.20 (2009).

    Google Scholar 

  49. Palmer, S. et al. Low-level viremia persists for at least 7 years in patients on suppressive antiretroviral therapy. Proc. Natl Acad. Sci. USA 105, 3879–3884 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Sharma, A. et al. A new class of multimerization selective inhibitors of HIV-1 integrase. PLoS Pathog. 10, e1004171 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  51. Livak, K. J. & Schmittgen, T. D. Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method. Methods 25, 402–408 (2001).

    Article  CAS  PubMed  Google Scholar 

  52. Hung, M. et al. Large-scale functional purification of recombinant HIV-1 capsid. PLoS ONE 8, e58035 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Pornillos, O., Ganser-Pornillos, B. K., Banumathi, S., Hua, Y. & Yeager, M. Disulfide bond stabilization of the hexameric capsomer of human immunodeficiency virus. J. Mol. Biol. 401, 985–995 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Perez-Riverol, Y. et al. The PRIDE database and related tools and resources in 2019: improving support for quantification data. Nucleic Acids Res. 47, D442–D450 (2019).

    Article  CAS  PubMed  Google Scholar 

  55. Maldonado-Baez, L. & Wendland, B. Endocytic adaptors: recruiters, coordinators and regulators. Trends Cell Biol. 16, 505–513 (2006).

    Article  CAS  PubMed  Google Scholar 

  56. Faini, M., Beck, R., Wieland, F. T. & Briggs, J. A. Vesicle coats: structure, function, and general principles of assembly. Trends Cell Biol. 23, 279–288 (2013).

    Article  CAS  PubMed  Google Scholar 

  57. Bethune, J., Wieland, F. & Moelleken, J. COPI-mediated transport. J. Membr. Biol. 211, 65–79 (2006).

    Article  CAS  PubMed  Google Scholar 

  58. Cvitkovic, I. & Jurica, M. S. Spliceosome database: a tool for tracking components of the spliceosome. Nucleic Acids Res. 41, D132–D141 (2013).

    Article  CAS  PubMed  Google Scholar 

  59. Ibarra, A. & Hetzer, M. W. Nuclear pore proteins and the control of genome functions. Genes Dev. 29, 337–349 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Ruegsegger, U., Beyer, K. & Keller, W. Purification and characterization of human cleavage factor Im involved in the 3’ end processing of messenger RNA precursors. J. Biol. Chem. 271, 6107–6113 (1996).

    Article  CAS  PubMed  Google Scholar 

  61. Nakagawa, S., Yamazaki, T. & Hirose, T. Molecular dissection of nuclear paraspeckles: towards understanding the emerging world of the RNP milieu. Open Biol. 8, 180150 (2018).

  62. Galganski, L., Urbanek, M. O. & Krzyzosiak, W. J. Nuclear speckles: molecular organization, biological function and role in disease. Nucleic Acids Res. 45, 10350–10368 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Tanaka, K. The proteasome: overview of structure and functions. Proc. Jpn Acad. B Phys. Biol. Sci. 85, 12–36 (2009).

    Article  CAS  Google Scholar 

  64. Zhou, X., Liao, W. J., Liao, J. M., Liao, P. & Lu, H. Ribosomal proteins: functions beyond the ribosome. J. Mol. Cell. Biol. 7, 92–104 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Garrod, D. & Chidgey, M. Desmosome structure, composition and function. Biochim. Biophys. Acta 1778, 572–587 (2008).

    Article  CAS  PubMed  Google Scholar 

  66. Kabsch, W. XDS. Acta Crystallogr. D. 66, 125–132 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  67. McCoy, A. J. et al. Phaser crystallographic software. J. Appl. Crystallogr. 40, 658–674 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  68. Adams, P. D. et al. PHENIX: a comprehensive Python-based system for macromolecular structure solution. Acta Crystallogr. D. 66, 213–221 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  69. Afonine, P. V. et al. Towards automated crystallographic structure refinement with phenix.refine. Acta Crystallogr. D 68, 352–367 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. Emsley, P., Lohkamp, B., Scott, W. G. & Cowtan, K. Features and development of Coot. Acta Crystallogr. D. 66, 486–501 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

Purified recombinant Sec23A/Sec24C and Sec23A/Sec24D proteins were a gift from R. Lesch, University of California Berkeley. We are grateful to M. Dzieciatkowska, University of Colorado School of Medicine Biological Mass Spectrometry Facility, for her help with proteomics studies. We thank P. Bieniasz, the Rockefeller University, for insightful discussions and advice. We are grateful to P. Koneru, S. Bester, K.-E. Lee, Y. Pan and other members of the participating laboratories for their help with data analysis, providing some reagents and valuable suggestions. This work was supported by the National Institutes of Health grant nos. R01 AI062520 and R01 AI157802 (to M.K.), U54 GM103368 (to M.K., A.C.F. and G.B.M.), R01 AI129862 (to G.B.M.), KL2 TR001068 (to R.C.L.) and R01 AI77344 (to E.M.P).

Author information

Authors and Affiliations

Authors

Contributions

S.V.R., G.W., R.C.L., J.L., A.C.F., A.S.A., J.M., N.S. and S.W. H. performed the experiments and/or analysed the experimental results. V.K.R., E.M.P., G.B.M. and M.K. designed and supervised separate sections of the study. M.K., together with S.V.R. and G.W., conceived the entire study and wrote the manuscript with contributions from all other authors.

Corresponding author

Correspondence to Mamuka Kvaratskhelia.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Microbiology thanks Edward M. Campbell, David Melville and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Identification of Sec24C as HIV-1 CA-interacting partner.

a, Experimental design of the MS-based proteomics approach (See Online Methods for details). b, Representative immunoblots showing CA tubes mediated pull-downs of endogenous Sec24C from THP1 cells without (lanes 1–5) or with (lanes 6–10) IFN treatments. Lanes 1 and 6: lysates, 2 and 7: supernatant or unbound fraction after pulldown in the absence of CA tubes, 3 and 8: supernatant or unbound fraction after pulldown in the presence of CA tubes; 4 and 9: pelleted or bound fraction in the absence of CA tubes; 5 and 10: pelleted or bound fraction in the presence of CA tubes.

Extended Data Fig. 2 Effects of Trim-Sec24C196–314 on different retroviruses.

(a) Representative immunoblot showing the stable expression of Trim-HA (blue line), Trim-CPSF6261–358 (orange line) and Trim- Sec24C196–314 (grey line) in HeLa cells. (b-h) Infections of HeLa cells stably expressing indicated Trim-fusion constructs with following VSV-G pseudotyped viruses: HIV-1NL4-3 (b), SIVmac239 (c), SIVstm (d), SIVsmE041 (e), FIV (f), EIAV (g), MLV (h). Infection levels of HIV-1-scarlet, SIVstm-eGFP, SIVmac239- eGFP, SIVsmE041-eGFP, FIV-eGFP, EIAV-eGFP, and MLV-RFP were determined by FACS. The averaged data (mean values ± SD) from three independent experiments are shown with exception of FIV infection in Trim-HA overexpressing and EIAV infection in Trim-CPSF6261–358 overexpressing Hela cells which were obtained from two independent experiments.

Extended Data Fig. 3 Comparative analysis of corresponding protein regions from Sec24C and Sec24D.

a, Sequence alignment of corresponding N-terminal regions of Sec24C and Sec24D are shown. The full-length proteins (NCBI ref sequences: NP_004913.2 and NP_055637.2) were aligned using Clustal Omega program from EMBL-EBI. The CA-binding FG-motif in Sec24C is highlighted in yellow and the FG residues are underlined with red. b, Effects of stably expressing Trim-Sec24C196–314 and Trim-Sec24D136–256 on HIV-1 infection in HeLa cells. The data (mean values +/− SD) from three independent experiments are shown.

Extended Data Fig. 4 Comparative analysis of full-length Sec23A/Sec24C and Sec23A/Sec24D for their interactions with CA tubes in vitro.

Interactions of purified recombinant Sec23A/Sec24C and Sec23A/Sec24D heterodimers with pre-assembled HIV-1 CA(A92E) tubes were analysed. Since Sec23A/Sec24C and Sec23A/Sec24D heterodimers were not sufficiently soluble in a 2 M NaCl containing buffer needed for assembly WT CA tubes, we used CA(A92E) which allowed us to effectively assemble the tubes with 1 M NaCl. In turn, the lower ionic strength conditions enabled us to avoid a background precipitation of the Sec23A/Sec24C and Sec23A/Sec24D heterodimers. a, A representative SDS–PAGE image of stock solutions of Sec23A/Sec24C, Sec23A/Sec24D and CA(A92E) proteins visualized by BlueFast Protein Staining Solution. b-c, Representative immunoblotting images of Sec23A/Sec24C (b) and Sec23A/Sec24D (c) interactions with CA(A92E) tubes. The Sec23A/Sec24C and Sec23A/Sec24D heterodimers were diluted to 0.03 mg/ml for the pulldown assays to avoid background protein precipitation. Lanes 1: load of Sec23A/Sec24C (b) or Sec23A/Sec24D (c); Lanes 2: pull-downs in the absence of CA; Lanes 3: pre-assembled CA(A92E) tubes were incubated with Sec23A/Sec24C (b) or Sec23A/Sec24D (c) in the assembly buffer. The mixture was centrifuged and washed three times with the buffer containing 50 mM Tris- HCl, pH 7.5, 1 M NaCl, 0.01% NP40, 2% glycerol. The pelleted fractions were run on SDS–PAGE and visualized by Sec24C (b) or Sec24D (c) antibody.

Extended Data Fig. 5 Analysis of cytoplasmic HIV-1 core colocalization with Sec24C.

TZM-bl cells transiently expressing Sec24C-mCherry were infected with INmNG-labelled HIV-1 bearing WT CA or the N74D CA mutant. At 2 hpi, cells were analysed for colocalization of INmNG-labelled WT or mutant N74D virus with Sec24C. (a) Representative images and (b) quantification of Sec24C-mCherry signal associated with INmNG-labelled puncta. The results are from n = 1202 WT/CA puncta from 43 cells and n = 1202 N74D/CA puncta from 25 cells. Colocalization (%) of the Sec24C-mCherry signal with INmNG puncta is shown in the graph. The averaged data are representative of two independent experiments. Statistical significance was determined by two-tailed student t-test. Arrows in (a) point to Sec24C-mCherry puncta colocalized with INmNG spots. Scale bar is 5 µm.

Extended Data Fig. 6 Effects of Sec24C KD on infectivity of HIV-1 (WT CA) and HIV-1 (N74D CA).

a, Representative immunoblot for the siRNA-mediated KD of Sec24C in HeLa cells. b and c, Infectivity (normalized to negative control KD) of VSV-G pseudotyped HIV-1 virus in WT and Sec24C KD HeLa cells without (b) and with (c) 1 µg/ml Aphidicolin. d-e, Infectivity (normalized to negative control KD) of VSV-G pseudotyped HIV-1 N74D CA mutant virus in WT and Sec24C KD HeLa cells without (d) and with (e) 1 µg/ml Aphidicolin. The data (mean values ± SD) from three independent experiments are shown. Statistical significance was determined by two-tailed student t-test.

Extended Data Fig. 7 Effects of GST-Sec24C196–314 on stability of isolated native HIV-1 cores.

VSV- G pseudotyped HIV-1 particles fluorescently labelled with INmNG (green) were bound to a poly-lysine-coated coverslip and treated with Saponin (100 μg/ml, 1 min) to expose the viral cores. Cores were either fixed immediately after saponin treatment (0 min) or after 10 min incubation at 37 °C with 25 μM of GST- Sec24C196–314, GST-Sec24C196–314(ΔFG) or with buffer (mock). After PFA fixation the cores were incubated with 100 nM of recombinant CypA-DsRed to bind the mature viral cores. (a) Representative images show INmNG and CypA-DsRed labelled HIV-1 cores after 0 and 10 min of incubation in the presence of GST-Sec24C196–314, GST-Sec24C196–314(ΔFG) or buffer. Dashed white circles show INmNG and CypA-DsRed co-localized puncta. Scale bar is 2 μm. (b) The data (mean values ± SD) from three independent experiments are shown. Statistical significance was determined by two-tailed student t-test.

Extended Data Fig. 8 Effects of GST-Sec24C196–314 on the stability of CA tubes.

(a-c) Stability of CA tubes as a function of time. CA tubes were preformed at 2 M NaCl, pelleted and then resuspended in a 1 M NaCl containing buffer to induce disassembly of the tubes (a). GST-Sec24C196–314(ΔFG) (b) or GST-Sec24C196–314 (c) was added to pre-formed CA tubes and then reactions were diluted to 1 M NaCl buffer. The mixtures were centrifuged at indicated time points and pellets were analysed by SDS–PAGE. (d) Quantification of the results in (a–c). The data (mean values ± SD) from three independent experiments are shown.

Extended Data Fig. 9 Effects of Sec24C KO and repletion on infection of different retroviruses.

Single-cycle replication assays were performed in WT, Sec24C KO, KO + Sec24C, or KO + Sec24C(ΔFG) Jurkat cells. Infection levels (normalized to WT Jurkat cells) of VSV-G pseudotyped eGFP reporter viruses: HIV-1 (a), SIVmac239 (b), SIVstm (c), SIVsmE041 (d), FIV (e), EIAV (f), MLV (g) were measured by FACS. The data (mean values ± SD) from three independent experiments are shown. (h) P-values. Statistically significant changes were observed for all lentiviruses, when their infection levels were compared for KO vs WT, KO + WT vs KO and KO + ΔFG vs KO + WT. In contrast, no statistically significant differences were seen for FIV or MLV across these cell lines. Sec24C KO resulted in slight but statistically significant increase of EIAV infection (KO vs WT). This effect is opposite to Sec24C KO effects on primate lentiviruses. Furthermore, in complete contrast with primate lentiviruses, no detectable differences were observed for EIAV in KO + ΔFG vs KO + WT cells. Statistical significance was determined by two-tailed student t-test.

Extended Data Fig. 10 Comparative analyses of interactions of cognate cellular proteins and PF74 inhibitor with CA.

a–c, Superimposition of the x-ray crystal structures of the Sec24C peptide (magenta) with CPSF6 peptide (blue) (a), Nup153 peptide (red) (b) and PF74 (black) (c) binding sites. d-f, Competition assays to show CPSF6 (d) and Nup153 (e) pull-downs from HeLa cell lysates by CA tubes in the absence (lane 3) and presence (lanes 4) of GST-Sec24C196–314. Representative immunoblots for CPSF6 and Nup153 are shown for the following samples. Lanes: 1, cellular lysates; 2, pelleting of cellular lysates in the absence of CA tubes; 3, pelleting of cellular lysates with CA tubes; 4, pelleting of cellular lysates with CA tubes + 2- fold excess GST-Sec24C196–314. (f), PF74 dose-dependent inhibition of interactions of GST-Sec24C196–314 with HIV-1 cores. The data (mean values +/− SD) from three independent experiments are shown. The results were analysed by Origin 2019 software to determine the IC50 value.

Supplementary information

Supplementary Information

Supplementary Figs. 1–8 and Tables 3–7.

Reporting Summary

Peer Review File

Supplementary Tables

Supplementary Table 1. Total spectrum counts of protein hits. Supplementary Table 2. Quantitative values for protein hits.

Supplementary Video 1

HIV-1 cores interact with Sec24C in living cells. TZM-bl cells transiently expressing mCherry-Sec24C fusion protein were infected with INsfGFP-labelled HIVeGFP pseudoviruses. Live-cell imaging of a single virus co-trafficking with Sec24C was performed for 45 min, starting from 1 hpi using a Zeiss LSM880 confocal microscope. Individual tiles of images corresponding to INsfGFP (green), mCherry-Sec24C (red), EBFP2-Lamin labelled nuclear membrane (blue) and merged channel are shown. The single particle track is highlighted. Scale bar, 5 µm.

Supplementary Video 2

HIV-1 cores interact with Sec24C in living cells. TZM-bl cells transiently expressing SNAP-Sec24C fusion protein were infected with CypA-DsRed-labelled HIVeGFP pseudoviruses. Live-cell imaging of a single virus co-trafficking with Sec24C at the perinuclear area was performed for 45 min, starting from 2 hpi using a Zeiss LSM880 confocal microscope. Individual tiles of images corresponding to SNAP-Sec24C (green), CypA-DsRed (red), EBFP2-Lamin labelled nuclear membrane (blue) and merged channel are shown. The multiple colocalized single particle tracks are highlighted. Scale bar, 5 µm.

Supplementary Video 3

HIV-1 cores interact with Sec24C in living cells. TZM-bl cells transiently expressing SNAP-Sec24C fusion protein were infected with HIVeGFP pseudoviruses co-labelled with INsfGFP and CypA-DsRed. Live-cell imaging of multiple HIV-1 cores co-trafficking with Sec24C was performed for 60 min, starting at 1 hpi using a Zeiss LSM880 confocal microscope. Individual tiles of images corresponding to INsfGFP (green), CypA-DsRed (red), SNAP-Sec24C (grey), EBFP2-Lamin labelled nuclear membrane (blue) and merged channel are shown. The single particle track is highlighted. Scale bar, 5 µm.

Source data

Source Data Fig. 1

Unprocessed gels and western blots.

Source Data Fig. 2

Statistical data.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Rebensburg, S.V., Wei, G., Larue, R.C. et al. Sec24C is an HIV-1 host dependency factor crucial for virus replication. Nat Microbiol 6, 435–444 (2021). https://doi.org/10.1038/s41564-021-00868-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41564-021-00868-1

This article is cited by

Search

Quick links

Nature Briefing Microbiology

Sign up for the Nature Briefing: Microbiology newsletter — what matters in microbiology research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Microbiology