HER2
HER2 (erb-b2 receptor tyrosine kinase 2, encoded by ERBB2) is a member of the EGF receptor family of receptor tyrosine kinases. Also known as NEU, HER-2, CD340 and p185(erbB2), it partners with ligand-bound family members to enhance downstream signalling. Browse Assay Genie's current range of HER2 research reagents below, or read on for the biology behind the target.
HER2 is a receptor tyrosine kinase of the EGF receptor subfamily, within the Tyr protein kinase family and the wider protein kinase superfamily. Unlike its relatives, it has no ligand binding domain of its own and cannot bind growth factors directly. Instead it binds tightly to other ligand-bound EGF receptor family members, such as ERBB4, to form heterodimers. This stabilises ligand binding and enhances kinase-mediated activation of downstream signalling, including the mitogen-activated protein kinase and phosphatidylinositol-3 kinase pathways.
HER2 is not confined to the plasma membrane. UniProt records it at the cell membrane and ruffle membrane, in early endosomes, in the perinuclear cytoplasm and in the nucleus. In the nucleus it is involved in transcriptional regulation: it associates with the 5'-TCAAATTC-3' sequence in the PTGS2/COX-2 promoter and activates transcription of that gene. It has also been implicated in transcriptional activation of CDKN1A, a function that involves STAT3 and SRC, and in the transcription of rRNA genes by RNA Pol I, where it enhances protein synthesis and cell growth.
The ERBB2 gene has several alternative transcript variants, some encoding different isoforms. Allelic variation has been reported at amino acid positions 654 and 655 of isoform a, with Ile654/Ile655 the most common allele. Amplification and/or overexpression of the HER2 gene has been reported in numerous cancers, including breast and ovarian tumours. The HGNC gene group places it among CD molecules (as CD340) and Erb-b2 receptor tyrosine kinases. Earlier names refer to the v-erb-b2 avian erythroblastic leukaemia viral oncogene homolog 2, and it is also known as neuro/glioblastoma derived oncogene homolog.
Amplification and overexpression of HER2 are reported in numerous cancers, including breast and ovarian tumours, making it a central subject in oncology research.
HER2 binds ligand-bound EGF receptor family members to form heterodimers, so it is widely used to study how partner pairing shapes receptor activation.
HER2 enhances activation of the MAPK and phosphatidylinositol-3 kinase pathways, which makes it relevant to studies of growth signalling.
Nuclear HER2 activates PTGS2/COX-2 and CDKN1A transcription and supports rRNA gene transcription, opening questions beyond classical membrane signalling.
HER2 is a receptor tyrosine kinase that cannot bind growth factors itself. It heterodimerises with ligand-bound EGF receptor family members, stabilising ligand binding and enhancing signalling through the MAPK and phosphatidylinositol-3 kinase pathways. In the nucleus it also contributes to transcriptional regulation.
The gene symbol is ERBB2, and aliases include NEU, HER-2, CD340, c-ERB2, c-ERB-2, MLN-19, p185(erbB2) and NGL. Older names describe it as a v-erb-b2 avian erythroblastic leukaemia viral oncogene homolog 2. Several transcript variants encode different isoforms, so check isoform coverage when choosing reagents.
Mouse and rat both carry an orthologous gene, Erbb2. In humans, amplification and/or overexpression of HER2 has been reported in numerous cancers, including breast and ovarian tumours. Check the datasheet of any product for its validated reactivity.
Other EGF receptor family members and signalling or transcriptional partners linked to HER2 with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P04626; product specifications from Assay Genie datasheets.