Disease relevance of SH3GLB1

• While Bif-1 expression was detected in 24 cases (40%) of the gastric carcinomas, there was no Bif-1 immunostaining in the remaining 36 cancers [1].
• The aim of this study was to explore whether alteration of Bif-1 expression might be a characteristic of gastric cancer [1].
• METHODS: We analysed the expression of Bif-1 protein in 60 gastric adenocarcinomas by immunohistochemistry using a tissue microarray approach [1].

High impact information on SH3GLB1

• We also show that endophilin B1 translocates to the mitochondria during the synchronous remodeling of the mitochondrial network that has been described to occur during apoptosis [2].
• Down-regulation of this protein or overexpression of endophilin B1 lacking the NH(2)-terminal lipid-modifying domain causes striking alterations of the mitochondrial distribution and morphology [2].
• Similar results were obtained in Bif-1 knockout mouse embryonic fibroblasts [3].
• Moreover, suppression of Bif-1 expression was associated with an enhanced ability of HeLa cells to form colonies in soft agar and tumors in nude mice [3].
• Together, our results suggest that the action of the endophilins is not confined to the formation of endocytic vesicles from the plasma membrane, with endophilin B1 being associated with, and presumably exerting a functional role at, intracellular membranes [4].

Biological context of SH3GLB1

• SH3GLB1 and SH3GLB2 do not significantly influence the onset and time course of Bax-mediated apoptosis in HeLa or 293T cells [5].
• SH3GLB1 shows strong similarities to the SH3 domain-containing proteins of the endophilin family and presumably represents the human homologue of the potential Caenorhabditis elegans SH3 containing-protein identified by systematic translation of the C. elegans genome (GenBank Accession No. U46675) [5].
• Overexpression of Bif-1 promotes Bax conformational change, caspase activation, and apoptotic cell death in FL5.12 cells following interleukin-3 deprivation [6].
• Bif-1 is an evolutionarily conserved cytoplasmic protein that contains a predicted Src homology 3 (SH3) domain located near its C terminus but shares no significant homology with members of the Bcl-2 family [6].
• The endophilin B1 gene gives rise to at least three splice variants, endophilin B1a, which shows a widespread tissue distribution, and endophilins B1b and B1c, which appear to be brain-specific [4].

Anatomical context of SH3GLB1

• A Northern blot analysis indicates that Bif-1 is expressed in most tissues with abundant expression in heart and skeletal muscle [6].
• Upon subcellular fractionation of brain and transfected fibroblasts, endophilin B1 is largely recovered in association with membranes [4].
• RESULTS: In normal gastric mucosal cells, surface and glandular epithelial cells strongly expressed Bif-1 [1].

Other interactions of SH3GLB1

• DLP1 also caused global morphological changes in MOM-like liposomes, but DLP1 did not stimulate BAX-permeabilizing function in the absence or presence of Bif-1 [7].

Analytical, diagnostic and therapeutic context of SH3GLB1

• Molecular cloning and characterization of Bif-1. A novel Src homology 3 domain-containing protein that associates with Bax [6].
• Bif-1 is capable of interacting with Bax as demonstrated by yeast two-hybrid, coimmunoprecipitation, and immunofluorescence studies [6].

References