HER2/CD340 Protein, Rat (HEK293, His)

HER2/CD340 protein, a multifaceted protein tyrosine kinase, serves as an essential component within various cell surface receptor complexes, requiring a coreceptor for ligand binding. Integral to neuregulin-receptor complexes, it collaborates with neuregulins, and GP30 emerges as a potential ligand for this receptor. Beyond its receptor roles, HER2/CD340 plays a pivotal role in regulating the outgrowth and stabilization of peripheral microtubules (MTs). Upon activation, the MEMO1-RHOA-DIAPH1 signaling pathway, triggered by ERBB2 activation, leads to GSK3B phosphorylation and subsequent inhibition at the cell membrane. This orchestrated inhibition prevents the phosphorylation of APC and CLASP2, facilitating their association with the cell membrane. The membrane-bound APC, in turn, facilitates the localization of MACF1 to the cell membrane, a critical step for microtubule capture and stabilization. Inside the nucleus, HER2/CD340 is involved in transcriptional regulation, associating with the 5'-TCAAATTC-3' sequence in the PTGS2/COX-2 promoter and activating its transcription. Additionally, it participates in the transcription of rRNA genes by RNA Pol I, enhancing protein synthesis and promoting cell growth. The multifaceted functions of HER2/CD340 underscore its central role in diverse cellular processes, from receptor signaling to microtubule dynamics and transcriptional regulation.