homeobox protein PBX1; pre-B-cell leukemia transcription factor 1; homeobox protein PRL (PBX1, PRL)

Function

• binds the sequence 5'-ATCAATCAA-3'
• acts as a transcriptional activator of PF4 in complex with MEIS1
• converted into a potent transcriptional activator by the (1;19) translocation
• may have a role in steroidogenesis &, subsequently, sexual development & differentiation
• forms a heterodimer with MEIS1 which binds DNA including a cAMP-responsive sequence in CYP17
• also forms heterotrimers with MEIS1 & a number of HOX proteins including HOXA9, HOXD4, HOXD9 & HOXD10
• interacts with PBXIP1

Structure

• belongs to the TALE/PBX homeobox family
• contains 1 homeobox DNA-binding domain

Compartment

nucleus (probable)

Alternative splicing

named isoforms=2

Expression

• expressed in all tissues except in cells of the B & T lineage

Pathology

• chromosomal translocation t(1;19)(q23;p13.3) involving PBX1 with TCF3 is a cause of pre-B-cell acute lymphoblastic leukemia (B-ALL)
• E2A-PBX1 transforms cells by constitutively activating transcription of genes regulated by PBX1 or by other members of the PBX protein family

More general terms

• homeobox protein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5087
• UniProt: http://www.uniprot.org/uniprot/P40424.html
• OMIM: https://mirror.omim.org/entry/176310
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5087