The identification and characterization of two phosphatidylinositol-4,5-bisphosphate 4-phosphatases

TMEM55B is a phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2) phosphatase.

“Transmembrane protein 55B (TMEM55B) is a phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2) phosphatase that regulates cellular cholesterol, modulates LDL receptor (LDLR) decay and lysosome function.”

TMEM55B is a late endosome/lysosome-localized type I phosphatase that converts PI(4,5)P2 to PI5P.

“TMEM55B was originally reported to be a late endosome/lysosome-localized type I phosphatase that converts phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2] to PI5P7.”

TMEM55B is a phosphatase that catalyzes the conversion of PI(4,5)P2 to PI5P.

“TMEM55B was originally reported to be a phosphatase that catalyzes the conversion of PI(4,5)P2 to PI5P7.”

TMEM55B is localized to the late endosome and lysosome.

“TMEM55B is localized to the late endosome and lysosome7, and has been shown to impact lysosome function23, 28.”

TMEM55B was first identified as a PI(4,5)P2 phosphatase by Ungewickell et al, but a recent study by Willett et al failed to detect PI(4,5)P2 hydrolysis activity of TMEM55B.

“Although TMEM55B was first identified as a PI(4,5)P2 phosphatase by Ungewickell et al7, a recent study by Willett et al failed to detect PI(4,5)P2 hydrolysis activity of TMEM55B28.”

TMEM55B is a lysosomal protein implicated in regulating lysosomal positioning and phosphatidylinositol 5-monophosphate abundance in the nucleus.

“TMEM55B is a lysosomal protein implicated in regulating lysosomal positioning and phosphatidylinositol 5-monophosphate abundance in the nucleus (Ungewickell et al. 2005), (Zou et al. 2007).”

TMEM55B was long considered a lysosomal protein of unknown function, though it regulates nuclear phosphatidylinositol-5-monophosphate.

“TMEM55B was long considered a lysosomal protein of unknown function, though it regulates nuclear phosphatidylinositol-5-monophosphate (Ungewickell et al. 2005), (Zou et al. 2007).”

TMEM55B overexpression mediates lysosomal degradation of internalized epidermal growth factor receptors.

“TMEM55B localizes to late endosomes and lysosomes and its overexpression mediates lysosomal degradation of internalized epidermal growth factor receptors (Ungewickell et al., 2005).”

TMEM55B localizes to late endosomes and lysosomes.

“TMEM55B localizes to late endosomes and lysosomes and its overexpression mediates lysosomal degradation of internalized epidermal growth factor receptors (Ungewickell et al., 2005).”