HP1α antibody (pAb)

HP1 (Heterochromatin protein 1) is a chromosomal protein that participates in both chromatin packaging and gene silencing. Three HP1 isoforms (a, b and g) occur in mammals. The chromodomain (Chromatin Organization Modifier) of HP1a is responsible for binding to Histone H3 methyl Lys9, although additional factors are required to specify the HP1 targeting. The chromoshadow domain mediates interactions with a number of nuclear proteins, including SuvH39 (a Histone H3 Lysine methyltransferase), the DNA methyltransferases DNMT1 and DNMT3A or the large subunit of the chromatin assembly factor-1 (CAF-1). Dysfunction of HP1a plays a critical role in tumorigenesis, and is implicated in the invasive/metastatic phenotype of breast cancer.