The following text describes a protein:
Function:
Plays a role in vesicle-mediated secretory processes. Required for normal accumulation of secretory vesicles in hippocampus, pituitary and pancreatic islets. Required for the accumulation of normal levels of insulin-containing vesicles and preventing their degradation. Plays a role in insulin secretion in response to glucose stimuli. Required for normal accumulation of the neurotransmitters norepinephrine, dopamine and serotonin in the brain. In females, but not in males, required for normal accumulation and secretion of pituitary hormones, such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Required to maintain normal levels of renin expression and renin release. May regulate catalytic active protein-tyrosine phosphatases such as PTPRA through dimerization. Has phosphatidylinositol phosphatase activity; the PIPase activity is involved in its ability to regulate insulin secretion. Can dephosphorylate phosphatidylinositol 4,5-biphosphate (PI(4,5)P2), phosphatidylinositol 5-phosphate and phosphatidylinositol 3-phosphate (By similarity). Regulates PI(4,5)P2 level in the plasma membrane and localization of cofilin at the plasma membrane and thus is indirectly involved in regulation of actin dynamics related to cell migration and metastasis; upon hydrolysis of PI(4,5)P2 cofilin is released from the plasma membrane and acts in the cytoplasm in severing F-actin filaments (By similarity).
Subcellular Localization:
Cytoplasmic vesicle, secretory vesicle membrane; Single-pass type I membrane protein. Cytoplasmic vesicle, secretory vesicle, synaptic vesicle membrane; Single-pass type I membrane protein. Note=Predominantly found on dense-core secretory granules. Sorting to secretory granules in part is dependent of the N-terminal pro domain of the precursor and its interaction with CPE. Transiently found at the cell membrane, when secretory vesicles fuse with the cell membrane to release their cargo. Is then endocytosed and recycled to secretory vesicles involving clathrin-dependent AP2-mediated endocytosis. Recycled via STX6- but not TTTGN1/TGN38-containing compartments; [IA-2beta60]: Cytoplasmic vesicle, secretory vesicle membrane.
Domain:
The tyrosine-based internalization signal is proposed to function in clathrin-mediated endocytosis and recycling; The leucine-based sorting signal is proposed to function in trafficking at the plasma membrane.
Sequence:
MGPPLPLLLLLLLPPPLPRALPAPASARGRQLPGRLGCLFEDGLCGSLETCVNDGVFGRCQKVPVMDTYRYEVPPGALLHLKVTLQKLSRTGFTWQDDYTQRVIAQELANLPKAYLWHGEASGPARSLQQNADNEKWFSLEREVALAKTLRRYLPYLELLSQTPTANAHSRIDHETRPAKGEDSSPENILTYVAHTSALTYPPATRAKYPDNLLRPFSRLQPDELSPKVDGDIDKQKLIAALGAYTAQRLPGENDPEPRYLVHGSARAPRPFSATALSQRWPPPPGDAKDSPSMDDDTLLQSLLKDLQQNSEVDRLGPLKEEKADSVAGAIQSDPAEGSQESHGRGAEGQPREQTDAPETMLQDHRLSEVDDPVYKEVNRLSFQLGDLLKDYGSPLLPEGPLLEKSSREEIKKSEQPEEVLSSEEETAGVEHVRSRTYSKDLFERKPNSEPQPRRLEDQFQNRAPELWEDEESLKLAAQGPPSGGLQLEVQPSEEQQGYILTGNNPLSPEKGKQLMDQVAHILRVPSSFFADIKVLGPAVTFKVSANIQNMTTADVIKAAADNKDQLEKATGLTILQSGIRPKGKLKLLPHQEEQEDSTKFILLTFLSIACILGVLLASSLAYCLRHNSHYKLKDKLSGLGADPSADATEAYQELCRQRMAIRPQDRSEGPHTSRINSVSSQFSDGPMPSPSARSSTSSWSEEPVQSNMDISTGHMILAYMEDHLKNKNRLEKEWEALCAYQAEPNSSLVAQREENAPKNRSLAVLTYDHSRILLKSQNSHGSSDYINASPIMDHDPRNPAYIATQGPLPATVADFWQMVWESGCAVIVMLTPLSENGVRQCHHYWPDEGSNLYHVYEVNLVSEHIWCQDFLVRSFYLKNLQTNETRTVTQFHFLSWYDQGVPSSTRSLLDFRRKVNKCYRGRSCPIIVHCSDGAGRSGTYVLIDMVLNKMAKGAKEIDIAATLEHLRDQRPGMVQTKEQFEFALTAVAEEVNAILKALPQ