Rab GTPases are molecular switches that regulate membrane traffic. They are active in their GTP-bound form and inactive when bound to GDP.[1] The GTPase YPT1, and its mammalian homologue Rab1, regulate membrane-tethering events on three different pathways: autophagy, ER-Golgi, and intra-Golgi traffic.[2] In the yeast Saccharomyces cerevisiae, many of the ATG proteins needed for macroautophagy are shared with the biosynthetic cytoplasm to the vacuole-targeting (CVT) pathway that transports certain hydrolases into the vacuole. Both pathways require YPT1; however, only the macroautophagy pathway is conserved in higher eukaryotes. In the macroautophagy pathway, Rab1 mediates the recruitment of Atg1 to the PAS. Rab1 regulates macroautophagy by recruiting its effector, Atg1, to the PAS to tether Atg9 vesicles to each other or to other membranes.[3]
References
edit- ^ Mizuno-Yamasaki, Emi; Rivera-Molina, Felix; Novick, Peter (7 July 2012). "GTPase Networks in Membrane Traffic". Annual Review of Biochemistry. 81 (1): 637–659. doi:10.1146/annurev-biochem-052810-093700. PMC 3708692. PMID 22463690.
- ^ Barrowman, Jemima; Bhandari, Deepali; Reinisch, Karin; Ferro-Novick, Susan (November 2010). "TRAPP complexes in membrane traffic: convergence through a common Rab". Nature Reviews Molecular Cell Biology. 11 (11): 759–763. doi:10.1038/nrm2999. PMID 20966969. S2CID 20099084.
- ^ Wang, J.; Menon, S.; Yamasaki, A.; Chou, H.-T.; Walz, T.; Jiang, Y.; Ferro-Novick, S. (28 May 2013). "Ypt1 recruits the Atg1 kinase to the preautophagosomal structure". Proceedings of the National Academy of Sciences. 110 (24): 9800–9805. doi:10.1073/pnas.1302337110. PMC 3683756. PMID 23716696.