title: The mitochondrial fission adaptors Caf4 and Mdv1 are not functionally equivalent.
abstract: Mitochondrial fission in eukaryotes is mediated by protein complexes that encircle and divide mitochondrial tubules. In budding yeast, fission requires the membrane-anchored protein Fis1 and the dynamin-related GTPase Dnm1. Dnm1 is recruited to mitochondria via interactions with the adaptor proteins Caf4 and Mdv1, which bind directly to Fis1. Unlike Mdv1, a function for Caf4 in mitochondrial membrane scission has not been established. In this study, we demonstrate that Caf4 is a bona fide fission adaptor that assembles at sites of mitochondrial division. We also show that fission complexes may contain Caf4 alone or both Caf4 and Mdv1 without compromising fission function. Although there is a correspondence between Caf4 and Mdv1 expression levels and their contribution to fission, the two adaptor proteins are not equivalent. Rather, our functional and phylogenetic analyses indicate that Caf4 mitochondrial fission activity has diverged from that of Mdv1.
authors.affiliation: Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Qian
authors.initials: Q
authors.lastname: Guo
authors.forename: Sajjan
authors.initials: S
authors.lastname: Koirala
authors.forename: Edward M
authors.initials: EM
authors.lastname: Perkins
authors.forename: J Michael
authors.initials: JM
authors.lastname: McCaffery
authors.forename: Janet M
authors.initials: JM
authors.lastname: Shaw
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D063154:Mitochondrial Dynamics; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C519559:Caf4 protein, S cerevisiae; C429283:MDV1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins