Our research is focused on the roles of dynamin and dynamin-related proteins. In the first funding period, we identified and characterized the C. elegans dyn-1 locus, which encodes a homologue of human dynamin. A temperature-sensitive mutation in the GTPase domain causes rapid and reversible paralysis. Dynamin is enriched in synapses where it is important for synaptic vesicle recycling. The membrane localization of dynamin has been attributed to interactions with SH3 proteins, such as amphiphysins found in mammals. GFP-dynamin chimeras were used to study the mechanisms of synaptic localization. Surprisingly, the dynamin GTPase domain is sufficient for strong localization, which suggests that novel interactions contribute to synaptic localization. This raises the question which of the many dynamin binding interactions are important for dynamin localization and function in vivo.
In Specific Aim 1, Characterization of C. elegans Dynamin Binding Partners, we propose to investigate the interactions with the dynamin GTPase domain and the possible contributions of C. elegans amphiphysin homologues to membrane localization. Our use of C. elegans allows us to test the biological relevance of these interactions. The research was expanded to include functions of dynamin-related proteins in C. elegans and humans. We discovered that Drp1 is an important regulator of mitochondrial morphology. We hypothesize that Drp1 is a pinchase that severs mitochondria. This new role for a dynamin family member is very exciting, because the mechanisms that control mitochondrial distribution are largely unknown.
In Specific Aim 2, Classic and Reverse Genetic Analysis of C. elegans drp-1, we propose to investigate how loss-of-function and dominant interference of drp-1 affect mitochondria in live animals.
We aim to see drp-1 activity in real time.
In Specific Aim 3, Cellular and Biochemical Analysis of Human Drp1, we propose to investigate the functions of human Drp1 and eventually reconstitute Drp1 with isolated mitochondria. Thus, we will test whether mitochondria and clathrin coated vesicles utilize similar constriction mechanisms.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM051866-08
Application #
6525849
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Program Officer
Deatherage, James F
Project Start
1995-08-01
Project End
2003-07-31
Budget Start
2002-08-01
Budget End
2003-07-31
Support Year
8
Fiscal Year
2002
Total Cost
$299,927
Indirect Cost
Name
University of California Los Angeles
Department
Biochemistry
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Yamano, Koji; Fogel, Adam I; Wang, Chunxin et al. (2014) Mitochondrial Rab GAPs govern autophagosome biogenesis during mitophagy. Elife 3:e01612
Wexler-Cohen, Yael; Stevens, Grant C; Barnoy, Eran et al. (2014) A dynamin-related protein contributes to Trichomonas vaginalis hydrogenosomal fission. FASEB J 28:1113-21
Shen, Qinfang; Yamano, Koji; Head, Brian P et al. (2014) Mutations in Fis1 disrupt orderly disposal of defective mitochondria. Mol Biol Cell 25:145-59
Fares, Hanna; van der Bliek, Alexander M (2012) Analysis of membrane-bound organelles. Methods Cell Biol 107:239-63
Youle, Richard J; van der Bliek, Alexander M (2012) Mitochondrial fission, fusion, and stress. Science 337:1062-5
Head, Brian P; Zulaika, Miren; Ryazantsev, Sergey et al. (2011) A novel mitochondrial outer membrane protein, MOMA-1, that affects cristae morphology in Caenorhabditis elegans. Mol Biol Cell 22:831-41
van der Bliek, Alexander M; Payne, Gregory S (2010) Dynamin subunit interactions revealed. Dev Cell 18:687-8
Head, Brian; Griparic, Lorena; Amiri, Mandana et al. (2009) Inducible proteolytic inactivation of OPA1 mediated by the OMA1 protease in mammalian cells. J Cell Biol 187:959-66
Kanazawa, Takayuki; Zappaterra, Mauro D; Hasegawa, Ayako et al. (2008) The C. elegans Opa1 homologue EAT-3 is essential for resistance to free radicals. PLoS Genet 4:e1000022
Gandre-Babbe, Shilpa; van der Bliek, Alexander M (2008) The novel tail-anchored membrane protein Mff controls mitochondrial and peroxisomal fission in mammalian cells. Mol Biol Cell 19:2402-12

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