HER2/CD340 Protein, Rat (His)

HER2/CD340 Protein, a protein tyrosine kinase, serves as a crucial component within various cell surface receptor complexes, necessitating a coreceptor for ligand binding. While an essential element in the neuregulin-receptor complex, it notably requires the presence of neuregulins for interaction. Additionally, GP30 stands out as a potential ligand for this receptor. Beyond its receptor functions, HER2 plays a key role in the regulation of peripheral microtubules (MTs), influencing their outgrowth and stabilization. Upon activation, the MEMO1-RHOA-DIAPH1 signaling pathway induced by ERBB2 phosphorylates and inhibits GSK3B at the cell membrane, preventing the phosphorylation of APC and CLASP2. This, in turn, facilitates the association of membrane-bound APC with the cell membrane, enabling the localization of MACF1 crucial for microtubule capture and stabilization. Furthermore, HER2 exhibits diverse interactions, including its preferential binding to the tyrosine-phosphorylated form of CPNE3 at the cell membrane, particularly in a growth factor heredulin-dependent manner. In the nucleus, HER2 extends its influence to transcriptional regulation, associating with specific sequences in the PTGS2/COX-2 promoter and activating transcription. It is also implicated in the transcriptional activation of CDKN1A, a process involving STAT3 and SRC, contributing to rRNA gene transcription by RNA Pol I and enhancing protein synthesis and cell growth. The multifaceted roles of HER2 highlight its intricate involvement in cellular processes, spanning from membrane dynamics to transcriptional regulation.