Gene Section Review Atlas Genet Cytogenet Oncol Haematol. 2005; 9(1) 6 Atlas of Genetics and Cytogenetics in Oncology and Haematology OPEN ACCESS JOURNAL AT INIST-CNRS ERBB2 (erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian)) Patrizia Casalini, Marilena V Iorio Molecular Targeting Unit, Experimental Oncology Dept., Istituto Nazionale Tumori, Via Venezian, 1. 20133 Milano, Italy (PC, MVI) Published in Atlas Database: December 2004 Online updated version : http://AtlasGeneticsOncology.org/Genes/ERBB2ID162ch17q11.html DOI: 10.4267/2042/38148 This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence. © 2005 Atlas of Genetics and Cytogenetics in Oncology and Haematology Identity Other names: v-erb-b2; HER2; NEU; TKR1; NGL; Her-2/neu; C-erbB-2 HGNC (Hugo): ERBB2 Location: 17q11.2-q12 Probe(s) - Courtesy Mariano Rocchi, Resources for Molecular Cytogenetics. Note Tyrosine-kinase receptor (RTK). The HER family of RTKs consists of four receptors: epidermal growth factor receptor (EGFR, also called HER-1 or erbB-1), HER-2 (also called erbB-2 or Neu), HER-3 and HER-4 (also called erbB-3 and erbB-4, respectively). DNA/RNA Description Sequence length 30528; CDS 3768. 27 exons; total exon length 4477, max. exon length 969, min exon length 48. Number of SNPs 11. Polymorphisms: allelic variations at amino acid positions 654 and 655 of isoform (a) (positions 624 and 625 of isoform (b)) have been reported, with the most common Allele B1 (Ile- 654/Ile-655); allele B2 (Ile-654/Val-655); allele B3 (Val-654/Val-655). This nucleotide polymorphism could be associated with development of gastric carcinoma and with breast cancer risk, particularly among younger women. Transcription Alternative splicing results in several additional transcript variants, some encoding different isoforms and others that have not been fully characterized. mRNA Transcript Variant: This variant (1) represents the shorter transcript but encodes the longer isoform (a) (protein: erbB-2 isoform (a)). mRNA Transcript Variant: This variant (2) (protein: erbB-2 isoform (b) contains additional exons at its 5' end and lacks an alternate 5' noncoding exon, compared to variant (1). These differences result in translation initiation at an in-frame, downstream AUG and an isoform (b) with a shorter N-terminus compared to isoform (a). mRNA Transcript Variant: herstatin HER2-ECD 1300 bp alternative erbB-2 transcript that retains intron 8. This alternative transcript specifies 340 residues identical to subdomains I and II from the extracellular domain of p185erbB-2 followed by a unique C- terminal sequence of 79 aa encoded by intron 8. The herstatin mRNA is expressed in normal human fetal kidney and liver, but is at reduced levels relative to p185erbB-2 mRNA in carcinoma cells that contain an amplified erbB-2 gene. mRNA Transcript Variant: An alternative transcript form of the human homologous gene