Biochemical analysis of deacetylase activity of rice sirtuin OsSRT1, a class IV member in plants

Abstract

The role of plant sirtuins is slowly unwinding. There are only reports of H3K9Ac deacetylation by OsSRT1. This belongs to class IV sirtuin family with a longer C-terminus. Here C-terminus is required for ligand binding and catalysis. OsSRT1 can deacetylate the lys residues at the N terminal tail of both H3 and H4. It can also target the non-histone target, OsPARP1 playing a role in DNA damage repair pathway. Changes in the extent of different histone deacetylation by OsSRT1 is also related with different abiotic stress conditions. NAM and ADP-ribose has negative effect on OsSRT1 deacetylation.HighlightsOsSRT1 is capable of deacetylating various lysine residues of histone H3 and H4 as well as OsPARP1.The extra long C-terminus of OsSRT1 is required for its substrate binding and thus, its catalysis.On plant’s exposure to H2O2 and Arsenic toxicity, there is a relationship between increased expression of OsSRT1 and increased deacetylation of H3 and H4.

A cobB like protein in Oryza sativa indica regulates the mitochondrial machinery under stress conditions

“…These are also required for enzyme catalysis as well as its diversity. In OsSRT1, the extra long C-terminus is required for substrate binding and its catalysis [34]. In comparison, OscobB do not have any extended N- and C-terminal regions as can be seen from the sequence alignments (Fig1A) .…”