protein_function: Protein tyrosine kinase that is part of several cellsurface receptor complexes, but that apparently needs a coreceptorfor ligand binding. Essential component of a neuregulin-receptorcomplex, although neuregulins do not interact with it alone. GP30is a potential ligand for this receptor. Regulates outgrowth andstabilization of peripheral microtubules (MTs). Upon ERBB2activation, the MEMO1-RHOA-DIAPH1 signaling pathway elicits thephosphorylation and thus the inhibition of GSK3B at cell membrane.This prevents the phosphorylation of APC and CLASP2, allowing itsassociation with the cell membrane. In turn, membrane-bound APCallows the localization of MACF1 to the cell membrane, which isrequired for microtubule capture and stabilization.
HER2,neu(also known as ErbB-2) stands for "e;Human Epidermal growth factor Receptor 2"e; and is a protein giving higher aggressiveness in breast cancers. It is a member of the ErbB protein family, more commonly known as the epidermal growth factor receptor family. HER2,neu has also been designated as CD340(cluster of differentiation 340) and p185. It is encoded by the ERBB2 gene.HER2 is a cell membrane surface-bound receptor tyrosine kinase and is normally involved in the signal transduction pathways leading to cell growth and differentiation. It is encoded within the genome by HER2,neu, a known proto-oncogene. HER2 is thought to be an orphan receptor, with none of the EGF family of ligands able to activate it. However, ErbB receptors dimerise on ligand binding, and HER2 is the preferential dimerisation partner of other members of the ErbB family.1 The HER2 gene is a proto-oncogene located at the long arm of human chromosome 17(17q21-q22)2.