Endophilin B1/B2 Products

Description

Endophilins are among the best known BAR (Bin/Amphiphysin/Rvs) domain proteins. The highly conserved protein dimerisation domain is typically involved in membrane dynamics. Endophilin-B1, also known as SH3GLB1 (Src-Homology 3 Domain-containing GRB2-like protein B1) and BIF-1, is a 40 kDa protein that belongs to the endophilin family of molecules. It is a cytoplasmic and Golgi membrane protein that is expressed in neurons, striated (skeletal and cardiac) muscle cells, and placenta. Using SH3GLB1 in yeast two-hybrid screens, a second protein, SH3GLB2 (endophilin B2), was identified as an interacting partner. Endophilin-B1 plays a role in cell homeostasis. In neurons, Endophilin-B1 is phosphorylated by Cdk5, inducing homodimerization and autophagosome formation. In addition, it appears to play a role in the maintenance of mitochondrial integrity. Endophilin-B1 appears to cycle on-and-off the outer mitochondrial membrane (OMM), contributing to OMM integrity. And after the initiation of endocytosis, it also directs EEA1+ TrkA-containing endosomes back into the cell membrane for reuse. Human Endophilin-B1 is 365 amino acids (aa) in length. It possesses an N-terminal lipid-binding BAR (Bin/Amphiphysin/Rvs) domain (aa 27-261) that contains an internal coiled-coil region, and a C‑terminal SH3 domain that binds Pro-rich sequences on potential ligands (309-363). There are at least three potential splice variants for Endophilin-B1. Two are 42 and 43 kDa in size, and possess a 21 and 29 aa insertion after Ser190, respectively. A third potentially utilizes an alternative start site at Met101. Over aa 33-189, human Endophilin-B1 shares 98% aa sequence identity with mouse Endophilin-B1.

Bioinformatics

Uniprot	Q9Y371
Product By Gene ID	51100
Alternate Names	Endophilin B1/B2