homeobox protein Meis1 (MEIS1)

Function

• acts as a transcriptional regulator of PAX6
• acts as a transcriptional activator of PF4 in complex with PBX1 or PBX2
• required for hematopoiesis, megakaryocyte lineage development & vascular patterning
• may function as a cofactor for HOXA7 & HOXA9 in the induction of myeloid leukemias
• interacts with the N-terminal region of PBX1 to form a heterodimer which binds a cAMP-responsive sequence in the CYP17 promoter
• also forms heterodimers with PBX2
• forms heterotrimers with PBX1 or PBX2 & a number of HOX proteins including HOXA9, HOXD4 & HOXD9 where it acts as a non-DNA-binding partner
• also forms heterotrimers with PBX1 & HOX proteins including HOXD9 & HOXD10 where PBX1 is the non-DNA-binding partner

Structure

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

Compartment

nucleus (putative)

Alternative splicing

named isoforms=2

Expression

• expressed at low level in normal immunohepatopoietic tissues, including the fetal liver
• expressed in a subset of myeloid leukemia cell lines, with highest expression seen in those with a megakaryocytic- erythroid phenotype
• also expressed at high levels in the cerebellum

Pathology

• defects in MEIS1 could be a cause of susceptibility to restless legs syndrome type 7

More general terms

• homeobox protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4211
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4211
• OMIM: https://mirror.omim.org/entry/601739
• OMIM: https://mirror.omim.org/entry/612853
• UniProt: http://www.uniprot.org/uniprot/O00470.html