title: Direct binding of the dynamin-like GTPase, Dnm1, to mitochondrial dynamics protein Fis1 is negatively regulated by the Fis1 N-terminal arm.
abstract: Recruitment of a dynamin-like GTPase (Drp1/Dlp1/Dnm1) to membranes requires the mitochondrial dynamics protein Fis1. Mdv1 has been proposed to act as an adaptor between Fis1 and Dnm1 in Saccharomyces cerevisiae. We show that S. cerevisiae Fis1 binds directly to Dnm1 and to Mdv1. Two Fis1 regions have been previously implicated in Mdv1 recruitment: an N-terminal "arm" and a concave surface formed by evolutionarily conserved residues in the tetratricopeptide repeat domain. Perturbing either Fis1 region does not affect Mdv1 binding, but both regions influence Dnm1 binding. Fis1 lacking its N-terminal arm binds tightly to Dnm1, and binding is abolished by mutations to the Fis1 concave surface. The Fis1-Dnm1 interaction decreases more than 100-fold in the presence of the Fis1 arm, suggesting that the arm acts in an autoinhibitory manner to restrict access to the Dnm1 binding site on Fis1. Our data indicate that the concave surface of the Fis1 tetratricopeptide repeat-like domain is evolutionarily conserved to bind the dynamin-like GTPase Dnm1 and not Mdv1 as previously predicted.
authors: Department of Biology, The Johns Hopkins University, Baltimore, Maryland, 21218.
authors: Robert C
authors: RC
authors: Wells
authors: Department of Biology, The Johns Hopkins University, Baltimore, Maryland, 21218.
authors: Lora K
authors: LK
authors: Picton
authors: Department of Biology, The Johns Hopkins University, Baltimore, Maryland, 21218.
authors: Sarah C P
authors: SCP
authors: Williams
authors: Department of Biology, The Johns Hopkins University, Baltimore, Maryland, 21218.
authors: Frederick J
authors: FJ
authors: Tan
authors: Department of Biology, The Johns Hopkins University, Baltimore, Maryland, 21218; Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218. Electronic address: hill@jhu.edu.
authors: R Blake
authors: RB
authors: Hill
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D034281:Dynamins / Q000737:chemistry / Q000502:physiology*; D019143:Evolution, Molecular; D005656:Fungal Proteins / Q000737:chemistry; D020558:GTP Phosphohydrolases / Q000737:chemistry / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D008968:Molecular Conformation; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C464859:FIS1 protein, S cerevisiae; D005656:Fungal Proteins; C429283:MDV1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D020558:GTP Phosphohydrolases; C094774:DNM1 protein, S cerevisiae; D034281:Dynamins