Invitrogen™ ErbB3 Monoclonal Antibody (SP71)

ErbB3 (c-erbB-3/HER-3) is a member of the type I family of growth factor receptors and binds to ligands in the heregulin family. ErbB3 is over-expressed in a variety of tumors in the prostate, bladder, breast, stomach, pancreas, and colon. Heregulin and EGF stimulate tyrosine phosphorylation of c-erbB-3 to different extents. The ErbB3 gene is located on the long arm of human chromosome 12 (12q13) and is transcribed into a 6. 2kb mRNA which is translated into a 160/180 kDa glycoprotein. The ErbB3 gene encodes a transmembrane receptor tyrosine kinase due to alternative splicing and forms heterodimers with other EGF receptor family members that have kinase activity. Heterodimerization leads to the activation of pathways that lead to cell proliferation or differentiation. Alternate transcriptional splice variants encoding different isoforms of ErbB3 have been characterized. One ErbB3 isoform lacks the intermembrane region, is secreted outside the cell, and acts to modulate the activity of the membrane-bound form. Additional splice variants have also been reported, but they have not been thoroughly characterized.