Our ERBB2 / HER2 biomarker assay measures protein tyrosine kinase that is part of several cell surface receptor complexes, but that apparently needs a coreceptor for ligand binding. It is an essential component of a neuregulin-receptor complex, although neuregulins do not interact with it alone. GP30 is a potential ligand for this receptor. Regulates outgrowth and stabilization of peripheral microtubules (MTs). Upon ERBB2 activation, the MEMO1-RHOA-DIAPH1 signaling pathway elicits the phosphorylation and thus the inhibition of GSK3B at cell membrane. This prevents the phosphorylation of APC and CLASP2, allowing its association with the cell membrane. In turn, membrane-bound APC allows the localization of MACF1 to the cell membrane, which is required for microtubule capture and stabilization. In the nucleus, ERBB2 / HER2 proteins are involved in transcriptional regulation. Associates with the 5′-TCAAATTC-3′ sequence in the PTGS2/COX-2 promoter and activates its transcription. Implicated in transcriptional activation of CDKN1A; the function involves STAT3 and SRC. Involved in the transcription of rRNA genes by RNA Pol I and enhances protein synthesis and cell growth.
We perform the ERBB2 / HER2 biomarker assay using mass spectrometry to achieve high analytical specificity in the measure and quantification of these cell surface proteins in cells and tissues. ERBB2 proteins are known to promote the growth of cancer cells and can cause the cancer to metastasize to other parts of the body, making it a key target for oncological therapeutics.
