Histone H1 chaperone activity of TAF-I is regulated by its subtype-dependent intramolecular interaction

作者：Kajitani Kaori; Kato Kohsuke^*; Nagata Kyosuke^*

来源：Genes to Cells, 2017, 22(4): 334-347.

DOI：10.1111/gtc.12478

Linker histone H1 is involved in the regulation of gene activity through the maintenance of higher-order chromatin structure. Previously, we have shown that template activating factor-I (TAF-I or protein SET) is involved in linker histone H1 dynamics as a histone H1 chaperone. In human and murine cells, two TAF-I subtypes exist, namely TAF-I and TAF-I. TAF-I has a highly acidic amino acid cluster in its C-terminal region and forms homo- or heterodimers through its dimerization domain. Both dimer formation and the C-terminal region of TAF-I are essential for the histone chaperone activity. TAF-I exhibits less histone chaperone activity compared with TAF-I even though TAF-I and differ only in their N-terminal regions. However, it is unclear how subtype-specific TAF-I activities are regulated. Here, we have shown that the N-terminal region of TAF-I autoinhibits its histone chaperone activity via intramolecular interaction with its C-terminal region. When the interaction between the N- and C-terminal regions of TAF-I is disrupted, TAF-I shows a histone chaperone activity similar to that of TAF-I. Taken together, these results provide mechanistic insights into the concept that fine tuning of TAF-I histone H1 chaperone activity relies on the subtype compositions of the TAF-I dimer.

• 出版日期2017-4