PBX1

Pre-B-cell leukemia transcription factor 1 is a protein that in humans is encoded by the PBX1 gene.^[5] The homologous protein in Drosophila is known as extradenticle, and causes changes in embryonic development.

PBX1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1B72, 1PUF
Identifiers
Aliases	PBX1, PBX homeobox 1, CAKUHED
External IDs	OMIM: 176310; MGI: 97495; HomoloGene: 20574; GeneCards: PBX1; OMA:PBX1 - orthologs
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1q23.3 Start 164,555,584 bp[1] End 164,899,296 bp[1]
Gene location (Mouse) Chr. Chromosome 1 (mouse)[2] Band 1 H2.3|1 75.95 cM Start 167,946,933 bp[2] End 168,259,839 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in tail of epididymis body of uterus pars reticulata ganglionic eminence buccal mucosa cell optic nerve myometrium canal of the cervix seminal vesicula Brodmann area 23 Top expressed in Rostral migratory stream habenula vas deferens genital tubercle olfactory bulb external carotid artery median eminence ventral tegmental area internal carotid artery ciliary body More reference expression data BioGPS More reference expression data
Gene ontology Molecular function sequence-specific DNA binding RNA polymerase II cis-regulatory region sequence-specific DNA binding protein heterodimerization activity DNA-binding transcription factor activity DNA binding DNA-binding transcription activator activity, RNA polymerase II-specific transcription factor binding protein binding RNA polymerase II transcription regulatory region sequence-specific DNA binding DNA-binding transcription factor activity, RNA polymerase II-specific Cellular component cytoplasm nucleus transcription regulator complex nucleoplasm RNA polymerase II transcription regulator complex Biological process anterior/posterior pattern specification proximal/distal pattern formation positive regulation of G2/M transition of mitotic cell cycle embryonic organ development embryonic hemopoiesis negative regulation of DNA-binding transcription factor activity transcription, DNA-templated sex differentiation multicellular organism development embryonic limb morphogenesis somatic stem cell population maintenance regulation of cell population proliferation adrenal gland development spleen development thymus development positive regulation of cell population proliferation urogenital system development regulation of transcription, DNA-templated regulation of ossification positive regulation of transcription by RNA polymerase II transcription by RNA polymerase II negative regulation of neuron differentiation embryonic skeletal system development branching involved in ureteric bud morphogenesis steroid biosynthetic process cell differentiation animal organ morphogenesis positive regulation of transcription of Notch receptor target Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 5087 18514 Ensembl ENSG00000185630 ENSMUSG00000052534 UniProt P40424 P41778 RefSeq (mRNA) NM_001204961 NM_001204963 NM_002585 NM_001353130 NM_001353131 NM_001291508 NM_001291509 NM_008783 NM_183355 RefSeq (protein) NP_001191890 NP_001191892 NP_002576 NP_001340059 NP_001340060 NP_001278437 NP_001278438 NP_032809 NP_899198 Location (UCSC) Chr 1: 164.56 – 164.9 Mb Chr 1: 167.95 – 168.26 Mb PubMed search [3] [4]
Wikidata
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Function

Mice studies suggest PBX1 is involved in bone generation and skeletal patterning.^[6]

Interactions

PBX1 has been shown to interact with:

• HOXB1,^[7][8]
• HOXB7,^[9]
• MEIS1,^[10][11][12] and
• Prep1.^[13]

Fruit fly homolog

The Drosophila melangoster gene called extradenticle encodes a homeodomain protein that is 71% similar to the Pbx1 protein, and is considered homologous to PBX1.^[14] extradenticle is a homeodomain transcription factor^[15] expressed during embryogenesis and is related to morphological changes and development.^[14]

Reduced levels of extradenticle cause segmental transformations, without affecting the functionality or location of homeotic genes. Complete removal of extradenticle both maternally and zygotically leads to alterations from failure of non-extradenticle protein expression.^[16]

A monoclonal antibody study of the expression of extradenticle protein in embryonic development found that it is uniformly distributed, as well as excluded from cell nuclei, until gastrulation. During the germ band retraction stage of development, extradenticle protein begins to accumulate in the nuclei of cells in a specific pattern. Proximal areas of wing and leg imaginal discs have extradenticle present in the nucleus, while distal areas only have it in the cytoplasm.^[17]