Periodic Tryptophan Protein 1 (PWP1)

Periodic tryptophan protein 1 homolog is a protein encoded by the PWP1 gene.The deduced aa sequence contains 9 Trp residues, some of which are localized in repeats and that characterise the protein as a member of the WD-40 family, a group of proteins having 40-aa repeats containing Trp and Asp. The protein contains a nuclear targeting signal (KKKGK), and fractionation of transformed human amnion cells (AMA) in karyoplasts and cytoplasts confirmed that it is predominantly localized in the nucleus. Database searching indicated that IEF SSP 9502 is a putative human homologue of the Saccharomyces cerevisiae periodic Trp protein, PWP1, a polypeptide that may play a regulatory role in cell growth and/or transcription.