Golgi-Associated PDZ and Coiled-Coil Motif Containing (GOPC) Human Recombinant Protein

This gene encodes a Golgi protein with a PDZ domain. The PDZ domain is globular and proteins which contain them bind other proteins through short motifs near the C-termini. Mice which are deficient in the orthologous protein have globozoospermia and are infertile. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2011]

PIST: a ubiquitously expressed peripheral membrane protein that contains a PDZ domain and two coiled-coil regions. Associates with the Golgi apparatus and plasma membrane, regulating intracellular protein trafficking and degradation. May play a role in autophagy, and regulate the intracellular trafficking of the ADRB1 receptor. Interacts with GOLGA3 and STX6. The PDZ domain is known to mediate interactions with CLCN3-iso2, ACCN3, CFTR, SSTR5, FDZ5, ADRB1, FZD8, GRID2, mGluR5, mGluR1. Mutations of PDZ residues S302D, T304E, K348D, K350E abrogates the ability of PIST to interact with the CFTR C terminus. May regulate CFTR chloride currents and acid-induced ACCN3 currents by modulating cell surface expression of both channels. Overexpression results in CFTR intracellular retention and degradation in the lysosomes. Enriched in synaptosomal and postsynaptic densities (PSD) fractions. Expressed in cell bodies and dendrites of Purkinje cells. Localized at the trans-Golgi network (TGN) of spermatids and the medulla of round spermatides. An oncogenic fusion protein between PIST (aka FIG) and the receptor tyrosine kinase ROS is found in glioblastoma multiform. Unlike other fusion RTK oncogenes, he mechanism of activation of PIST-ROS does not appear to be dimerization. Rather, activation of the fused ROS kinase appears to depend upon translocation to the golgi apparatus: deletion of 2nd coiled-coil region, crucial for Golgi localization, appears to eliminate the transformation capacity of PIST-ROS. Three alternatively spliced human isoforms have been described.

Protein type: Membrane protein, peripheral

Chromosomal Location of Human Ortholog: 6q21

Cellular Component: Golgi membrane; Golgi apparatus; postsynaptic membrane; trans-Golgi network transport vesicle; protein complex; membrane; postsynaptic density; cytoplasm; dendrite; plasma membrane; cell junction

Molecular Function: protein C-terminus binding; protein binding; protein homodimerization activity; frizzled binding

Biological Process: Golgi to plasma membrane transport; ER to Golgi vesicle-mediated transport; apical protein localization; protein transport; regulation of catalytic activity; spermatid nuclear differentiation; protein homooligomerization; cytoplasmic sequestering of CFTR protein

Disease: Spermatogenic Failure 6