Organelles articles from across Nature Portfolio

The structure of the Golgi and the localization of glycosylation enzymes remain largely elusive. Here, the authors use super-resolution microscopy to show that the Golgi is composed of small dynamic units which have rapidly moving zones of glycosylation enzymes.

In this study, the authors show that centriole 9-fold microtubule symmetry is not essential for centriole elongation, correct distribution of the centriole’s components along its length, and in initiating aspects of centriole duplication.

Liu, Zhen, Xie, Luo, Zeng, Zhao et al. show that the major nucleoid protein TFAM interacts with cytoplasmic LC3B during oxidative or inflammatory stress to attenuate mitochondrial DNA-induced inflammation via the cGAS–STING pathway.

Mitochondria, the powerhouse and the vital signaling hub of the cell, participate in a variety of biological processes, such as apoptosis, redox responses, cell senescence, autophagy, and iron homeostasis. Mitochondria form a mostly tubular network, made up of an outer and a cristeae-forming inner membrane. The network undergoes dynamic fusion and fission that change its morphological structure according to the functional needs. Approximately 1500 mitochondrial proteins encoded by nuclear genome plus over 10 proteins encoded by mitochondrial DNA are folded and assembled in the mitochondria under a high-fidelity control system. These proteins are involved in oxidative phosphorylation, metabolism, network and cristae dynamics, mitophagy, import machinery, ion channels, and mitochondrial DNA maintenance. This Collection gathers original research that advances our understanding of the monitoring techniques and pathophysiological significance of mitochondrial dynamics in health and disease.

We show that the mitochondrial fission proteins MiD49 and MiD51 are activated by fatty acyl-coenzyme A (FA-CoA). FA-CoA binds in a previously identified pocket located within MiDs, inducing their oligomerization and ability to activate the dynamin DRP1, ultimately promoting mitochondrial fission. Activated MiDs synergize with mitochondrial fission factor (MFF) in stimulating DRP1 activity, leading us to hypothesize that MiDs act upstream of MFF during mitochondrial fission.

Cellular and organismal aging have been consistently associated with mitochondrial dysfunction and inflammation. Accumulating evidence indicates that aging-related inflammatory responses are mechanistically linked to compromised mitochondrial integrity coupled with mtDNA-driven CGAS activation, a process that is tonically inhibited by mitophagy.

AMPK directly phosphorylates the mitochondrial protein SYNJ2BP to facilitate its interaction with the RNA-binding protein SYNJ2a, which transports Pink1 mRNA into neurites. AMPK inhibition downstream of insulin signalling untethers Pink1 mRNA from neuronal mitochondria and favours PINK1-dependent mitophagy in neurons. ApoE4-induced insulin receptor internalization reverses the process by stabilizing Pink1 mRNA binding to neuronal mitochondria.

The endoplasmic reticulum (ER) controls the synthesis of lipids and proteins and Ca²⁺ homeostasis, as well as contacting other organelles and the plasma membrane. A study now looks at a process by which this compartment is remodelled in axons during neurogenesis: the lysosomal clearance of ER subdomains, driven by FAM134 and CCPG1 proteins.

In this issue of Nature Metabolism, it is shown that the abundance of Caenorhabditis elegans branched-chain aminotransferase-1 (BCAT-1) — which catalyses the first step of branched-chain amino acid (BCAA) catabolism — declines sharply in aged wild-type nematodes but not in slowly ageing mutants, and that stimulating BCAA catabolism extends reproductive longevity.