A human POU domain gene, mPOU, is expressed in developing brain and specific adult tissues

Abstract

POU domain genes constitute a family of transcription factors that exhibit distinct temporal and spatial patterns of expression. To investigate the possible functions that POU proteins may have in muscle development we have isolated four novel POU‐domain‐encoding sequences from human muscle tissue. One of these sequences, referred to as mPOU, encodes a new member of subclass VI of the POU family. In the embryo, mPOU is expressed exclusively in the developing brain, whereas in the adult its expression is restricted to brain, heart, skeletal muscle and lung. In the brain, the highest expression levels were found in specific cell layers of the cortex, the olfactory bulb, the hippocampus and the cerebellum. mPOU is shown to bind to DNA sequences containing the octamer motif and other POU factor target sites. The distinct expression pattern and divergent DNA‐binding characteristics indicate that mPOU may regulate a distinct set of genes.

Molecular cloning and characterization of a human PAX-7 cDNA expressed in normal and neoplastic myocytes

“…In order to identify homeobox proteins expressed during mammalian myogenesis, we have used degenerated oligonucleotides in a polymerase chain reaction (PCR) to amplify homeobox sequences from human primary muscle cells. These experiments yielded several new homeobox sequences, one of which represented a new member of the POU family of homeobox proteins (41).…”

POU domain family values: flexibility, partnerships, and developmental codes.

“…I-POU Brn-3.0/Brn-3a (RDC-i, POU4F1) oogenesis and early embryo both: gap-like pattern in early embryo; peripheral sensory organs; neuroectoderm, neuroblasts; ectoderm; Pdm-1 only--throughout wing primordium B cells; alternative splice forms in nervous system skin (keratinocytes) all levels of CNS in embryo and adult--more restricted in adult; intestine, kidney overlapping expression in embryonic and adult nervous system; pronephric Wolffian duct all levels of CNS in embryo and adult--more restricted expression in adult [Z] all levels of CNS in embryo and adult [Z] all levels of CNS in embryo and adult [X l not described [M] all SpOct (Char et al 1993);zp-12, zp23, zp47 (Spaniol et al 1996);CEH-6 (Burglin et al 1989); RPF-1 ; pou[c] (Johansen et al 1993);Brn-5 (Andersen et al 1993c); emb (Okamoto et al, 1993); mPOU (Wey et al 1994); Cns-1 (Bulleit et al 1994). UTargeted disruption of the CD3 n locus affects Oct-1 transcription, which is encoded on the opposite strand.…”

A Novel Complex Regulates cardiac actin Gene Expression through Interaction of Emb, a Class VI POU Domain Protein, MEF2D, and the Histone Transacetylase p300

“…Tests of function with the shorter form of Emb have given contradictory results, and its potential transcriptional targets are ill defined. In vitro experiments with rat Brn5 (1) and human TCF␤1/mPOU (36) suggest that it may act as a transcriptional activator, while other experiments with human mPOU might suggest repression, possibly by competition with Oct1 (62). Based on our observations, we would suggest that it is involved in transcriptional activation, via chromatin remodeling, and that this probably involves the NH2 domain, absent from the shorter forms tested.…”

“…In order to establish which proteins are present in the complexes formed with the 3Ј ATrich fragment, competition experiments were performed with oligonucleotides to the consensus binding sites and with antibodies to transcriptional factors suspected of binding to the fragment. Since Emb is a candidate, the presence of the protein was verified in C2 muscle cell extracts by Western blot analysis, using an antibody directed against the human homologue, mPOU (62). This reveals a protein of about 80 kDa, which is not recognized by the preimmune serum (Fig.…”

“…Based on our observations, we would suggest that it is involved in transcriptional activation, via chromatin remodeling, and that this probably involves the NH2 domain, absent from the shorter forms tested. Emb/Brn5/mPOU are expressed in a number of adult tissues, including brain and striated muscle (1,36,42,62). Brn5 is high in postmitotic neurons, and overexpression of the 40-kDa form has a negative effect on proliferation, although it does not affect differentiation (8,9).…”