Distinct regions of the chicken p46 polypeptide are required for its in vitro interaction with histones H2B and H4 and histone acetyltransferase-1.
We cloned cDNA encoding the chicken p46 polypeptide, chp46, homologous to the p48 subunit of chicken chromatin assembly factor-1, chCAF-1p48. It comprises 424 amino acids including a putative initiation Met, is a member of the WD protein family, with seven WD repeat motifs, and exhibits 90.3% identity to chCAF-1p48 and 94.3% identity to the human and mouse p46 polypeptides (hup46 and mop46). The in vitro immunoprecipitation experiment established that chp46 interacts with histones H2B and H4 and chicken histone acetyltransferase-1, chHAT-1, whereas hup46 interacts with histones H2A and H4 and chHAT-1 and chCAF-1p48 with histone H4 and chHAT-1. The in vitro immunoprecipitation experiment, involving truncated mutants of chp46, revealed not only that two regions comprising amino acids 33-179 and 375-404 are necessary for its binding to H2B, but also that two regions comprising amino acids 1-32 and 405-424 are necessary for its binding to H4. Furthermore, the GST pulldown affinity assay, involving truncated mutants of chp46, revealed that a region comprising amino acids 359-404 (in fact, 375-404) binds to chHAT-1 in vitro. Taken together, these results indicate not only that chp46 should participate differentially in a number of DNA-utilizing processes through interactions of its distinct regions with chHAT-1 and histones H2B and H4, but also that the proper propeller structure of chp46 is not necessary for its interaction with chHAT-1.
Ahmad
A
A
Department of Biochemistry, Miyazaki Medical College, 5200, Kihara, Kiyotake, Miyazaki 889-1692, Japan.
Takami
Y
Y
Nakayama
T
T
D000123:Acetyltransferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens; D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051548:Histone Acetyltransferases; D006657:Histones / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid
D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; D000123:Acetyltransferases; D051548:Histone Acetyltransferases