Difference between revisions of "Phosphatase Subfamily MTMR6"

Revision as of 19:38, 31 December 2014

Phosphatase Classification: FoldCC1: Superfamily CC1: Family Myotubularin: Subfamily MTMR6

[Punch line]

Evolution

MTMR6 subfamily is found throughout holozoan. Human and most if not all vertebrates has three members per genome: MTMR6, MTMR7 and MTMR8. Other metazoan such as fruit fly and C elegans has a single member.

Domain Structure

MTMR6 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 MTMR3 subfamily, PH/GRAM domain can bind to phosphoinositide lipids. Coiled-coil domain has been shown to mediate the interaction with MTMR9 in human [1, 2, 3].

Catalytic activity and functions

The enzymatic activity of all three human MTMR6s are up-regulated by pseudophosphatase MTMR9 through protein interactions [1, 2, 3]. The interaction between MTMR9 and MTMR6 subfamily is also observed in C elegans [4].

Though all of MTMR6, MTMR7 and MTMR8 are 3-phosphatase, they have different preferences of substrates. MTMR6/R9 complex that regulates PtdIns (3, 5)P2 levels and thereby affects apoptosis; MTMR8/R9 complex down-regulates the levels of PthIns(3)P and blocks the autophagic process [2, 3]; MTMR7/MTMR9 dephosphorylates phosphatidylinositol 3-phosphate and Ins(1,3)P2 in neuronal cells [1].

MTMR7 has also been reported to regulate T-cell differentiation and Protein kinase B AKT signaling, possibly through regulation of phosphatidylinositol [3,4,5]-trisphosphate activity [5].

References

1. Error fetching PMID 12890864: [Mochizuki03]
2. Error fetching PMID 19038970: [zou09]
3. Error fetching PMID 22647598: [zou12]
4. Error fetching PMID 21076391: [marie10]