Npw38, a novel nuclear protein possessing a WW domain capable of activating basal transcription.
We have found a novel cDNA encoding a 265 amino acid protein possessing a WW domain in our full-length cDNA bank. The WW domain was sandwiched between an acidic region and an acidic-basic amino acid repetitive region. In vitro transcription/translation of the cDNA produced a 38 kDa product that was also found in the cell lysate by western blot analysis. Thus this protein is named the nuclear protein containing a WW domain with a molecular mass of 38 kDa, Npw38. Immunofluorescence studies and expression of a fusion protein to a green fluorescent protein revealed that this protein is localized in the nucleus. Npw38 was shown to be capable of binding to a poly(rG) resin. Interestingly, the WW domain of Npw38 was found to function as a transcriptional activator in CHO cells using the GAL4 DNA-binding fusion system. Furthermore, the WW domains of human YAP and Pin1 were demonstrated to have a similar transcription-promoting activity. Combined mutation of the conserved first and second Trp residues and a hydrophobic triplet of TyrTyrTrp in the WW domain of Npw38 abolished the transcription-promoting activity, but single mutations of these sites did not. These results suggest that some WW domains potentially possess transcription-promoting activity in mammalian cells.
Komuro
A
A
Kato Cytoprotein Network Project, ERATO, Japan Science and Technology Corporation (JST), c/o Sagami Chemical Research Center, Nishi-Ohnuma 4-4-1, Sagamihara, Kanagawa 229-0012, Japan.
Saeki
M
M
Kato
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002352:Carrier Proteins; D003001:Cloning, Molecular; D006224:Cricetinae; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C119246:PQBP1 protein, human; D012333:RNA, Messenger; D015534:Trans-Activators