Difference between revisions of "Phosphatase Subfamily MTMR1"

Revision as of 23:54, 13 April 2017

Phosphatase Classification: Fold CC1: Superfamily CC1: Family Myotubularin: Subfamily MTMR1

MTMR1 is a lipid phosphatase that dephosphorylates the second messenger phosphatidylinositol 3-monophosphate [PI(3)P].

Evolution

MTMR1 is found throughout holozoa [1]. It consists of three members in human, MTM1, MTMR1 and MTMR2. In fruit fly and C elegans, a single copy is found. In most vertebrates from fish to human, MTM1 and MTMR1 are adjacent on the X chromosome (see Genomicus).

Domain Structure

MTMR1 has a GRAM domain, phosphatase domain and coiled-coil region. The GRAM domain is similar to the PH domain in structure and is found in membrane-associated proteins. As shown in MTMR3 subfamily, the GRAM domain can bind to phosphoinositide lipids. The coiled-coil domain has been shown to mediate the interaction between MTMR2 and the MTMR5 subfamily members MTMR13 and MTMR5 in human [2, 3].

Catalytic activity and functions

Human MTM1 has phosphatase activity towards the second messenger phosphatidylinositol 3-monophosphate [PI(3)P] in vitro and in human [4, 5]. Human MTMR1 and MTMR2 have been shown to dephosphorylate PI(3)P ([6] and [7], respectively). Although the enzymatic properties of the three human phosphatases are indistinguishable, their functions are not totally redundant. MTM1 and MTMR2 are differentially regulated in the aspects of developmental expression and subcellular localization, resulting in their use of specific cellular pools of PI(3)P [7].

Related Kinases

See PI3K.

References

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