MUTATIONON WD DIPEPTIDEMOTIFSOF THE p48 SUBUNIT OF CHROMATIN ASSEMBLY FACTOR-1CAUSING VIABILITY AND GROWTHOF DT40 CHICKEN B CELL LINE

• Main Author: Perpustakaan UGM, i-lib
• Format: Article NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2009
• Subjects: Jurnal i-lib UGM
• Online Access: https://repository.ugm.ac.id/28088/; http://i-lib.ugm.ac.id/jurnal/download.php?dataId=11151
• Institution: Universitas Gadjah Mada

ABSTRACT Chromatin assembly factor-1 (CAF-1), a protein complex consisting of three subunits, p150, p60, and p48, is highly conserved from yeast to humans and facilitated nucleosome assembly of newly replicated DNA. The p48 subunit, CAF-1p48 (p48), with seven WD (Trp-Asp) repeat motifs, is a member orthe WD protein family. The immunoprecipitation experiment revealed that l3-propeller structure of p48 was less stringent for it's binding to HDAC-1, but more stringent for its binding to both histones H4 and CAF-1p60 but not to ASF-1, indicating that the proper l3-propeller structure of p48 is essential for the binding to these two proteins histone H4 and CAF-1p60. Complementation experiments, involving missense and truncated mutants of FLAG-tagged p48, revealed that mutations of every of seven WDdipeptide motifs, like both the N-terminal and C-terminal truncated mutations, could not rescue for the tet-induced lethality. These results indicate not only that p48 is essential for the viability of vertebrate cells, although the yeast p48 homolog is nonessential, but also that all the seven WDdipeptide motifs are necessary for the maintenance of the proper structure of p48 that is fundamentallyimportant for cell viability. Keywords: Chromatin assembly factor-1, complementation experiments, viability