Article
- The EMBO Journal (2002) 21, 6429 - 6439
- doi:10.1093/emboj/cdf644
Subject Categories:
XPak3 promotes cell cycle withdrawal during primary neurogenesis in Xenopus laevis
Jacob Souopgui1,2, Marion Sölter1 and Tomas Pieler1
- Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany
- Department of Biochemistry, Faculty of Science, University of Yaoundé I, PO Box 812, Yaoundé, Cameroon
Correspondence to:
Tomas Pieler, E-mail: tpieler@gwdg.de
Received 28 June 2002; Accepted 15 October 2002; Revised 19 September 2002
Abstract
We have isolated the Xenopus p21-activated kinase 3 (XPak3) by virtue of its expression in the territory of primary neurogenesis in the developing embryo. XPak3, but not the other Pak variants, responds positively to X-Ngnr-1 and negatively to X-Notch-1. A constitutively active form of XPak3, generated by fusing a myristylation signal to the N-terminus (XPak3-myr), induces early cell cycle arrest at high concentrations, while ectopic expression of low amounts induces premature neuronal differentiation. Conversely, XPak3 loss of function achieved by use of an antisense morpholino oligonucleotide increases cell proliferation and inhibits neuronal differentiation; this phenotype is rescued by co-injection of XPak3-myr. We conclude that XPak3 is a novel member of the proneural pathway, functioning downstream of neurogenin to withdraw neuronally programmed cells from the mitotic cell cycle, thus allowing for their differentiation.
Keywords:
- cell cycle regulation,
- neurogenesis,
- Xenopus laevis,
- XPak3
