PURB
Description
The PURB (purine rich element binding protein B) is a protein-coding gene located on chromosome 7.
The PURB gene encodes Pur-beta, a sequence-specific, single-stranded DNA-binding protein. It binds to the purine-rich element (PUR), found at replication origins and gene flanking regions in various eukaryotes. PURB is involved in both DNA replication and transcription control. Deletion of PURB is linked to myelodysplastic syndrome and acute myelogenous leukemia.
PURB acts as a transcriptional regulator, capable of both activating and repressing gene expression. It represses the transcription of ACTA2 in fibroblasts and smooth muscle cells by binding to a purine-rich element in the gene's regulatory region. PURB also represses the transcription of MYOCD, particularly affecting the SMC-specific isoforms. In the liver, PURB promotes glucose production by activating ADCY6, leading to increased cAMP, PKA activity, CREB activation, and transcription of PCK1 and G6PC. PURB binds to repeated elements in single-stranded DNA, such as the PUR element upstream of the MYC gene. It plays a role in the regulation of alpha-MHC expression in cardiac myocytes by binding to the PNR element and modulates galectin-3 gene transcription in the liver. PURB may be involved in the transport of specific mRNAs within dendrites. It forms homodimers, heterodimers with PURA, and heterotrimers with PURA and YBX1. PURB interacts with MYOCD and SRF.
PURB is also known as PURBETA.
