Myotubularin Related Protein 4 (MTMR4)

By database screening, Zhao et al. (2001) identified MTMR4, which they called FYVE-DSP2, and cloned the full-length cDNA from a human brain cDNA library. MTMR4 encodes an intracellular protein of 1,195 amino acids with a calculated molecular mass of 133.3 kD. MTMR4 shares about 47% overall sequence identity with MTMR3, and over 70% identity in the putative catalytic domain and the double zinc finger (FYVE) motif. By PCR analysis, Zhao et al. (2001) found expression of MTMR4 in all human tissues examined except lung, small intestine, stomach, salivary gland, adrenal gland, and uterus. Endogenous MTMR4 expressed by HeLa and human leukemic cells showed a molecular mass of 130 kD by Western blot analysis. Subcellular localization of MTMR4 in transfected HeLa cells showed a perinuclear distribution, similar to that seen with MTMR3.