Phosphatase Subfamily MTMR9
Phosphatase Classification: FoldCC1: Superfamily CC1: Family Myotubularin: Subfamily MTMR9
[Punch line is coming]
Evolution
MTMR9 is found throughout holozoan. It is usually single copy per genome.
Domain Structure
MTMR9 subfamily has three domains: PH/GRAM, phosphatase domain and coiled-coil domain. The GRAM domain is similar to PH domain in structure and is found in membrane-associated proteins. As shown in MTMR subfamily, PH/GRAM domain can bind to phosphoinositide lipids. In Monosiga, the GRAM is replaced by a C1 domain, which is also a lipid-binding domain. Coiled-coil domain has been shown to mediate the interaction between MTMR9 and members of MTMR6 in human [1, 2, 3].
Catalytic activity and functions
MTMR9 is an inactive phosphatase (pseudophosphatase). MTMR9 binds to phosphatases of MTMR6 subfamilies: MTMR6 [2], MTMR7 [1], MTMR8 [3]. The interactions increase the enzymatic activity of these phosphatases.
References
- Mochizuki Y and Majerus PW. Characterization of myotubularin-related protein 7 and its binding partner, myotubularin-related protein 9. Proc Natl Acad Sci U S A. 2003 Aug 19;100(17):9768-73. DOI:10.1073/pnas.1333958100 |
- Zou J, Chang SC, Marjanovic J, and Majerus PW. MTMR9 increases MTMR6 enzyme activity, stability, and role in apoptosis. J Biol Chem. 2009 Jan 23;284(4):2064-71. DOI:10.1074/jbc.M804292200 |
- Zou J, Zhang C, Marjanovic J, Kisseleva MV, Majerus PW, and Wilson MP. Myotubularin-related protein (MTMR) 9 determines the enzymatic activity, substrate specificity, and role in autophagy of MTMR8. Proc Natl Acad Sci U S A. 2012 Jun 12;109(24):9539-44. DOI:10.1073/pnas.1207021109 |
