Oligomerization and Auto-methylation of the Human Lysine Methyltransferase SETD6. Issue 21 (19th October 2018)

• Record Type: Journal Article
• Authors: Weil, Lital Estrella; Shmidov, Yulia; Kublanovsky, Margarita; Morgenstern, David; Feldman, Michal; Bitton, Ronit; Levy, Dan
• Is Part Of: Journal of molecular biology. Volume 430:Issue 21(2018)
• Page Start: 4359
• Page End: 4368
• Publication Date: 2018-10-19
• Subjects: SETD6 -- lysine methylation -- auto-methylation; PKMTs protein lysine methyltransferases -- SETD6 SET-domain-containing protein 6 -- S-adenosyl-l-methionine SAM -- SAH S-adenosyl-l-homocysteine -- SEC size exclusion column -- DLS dynamic light scattering; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2018.08.028
• Languages: English
• ISSNs: 0022-2836

Abstract

Abstract: Signaling via lysine methylation by protein lysine methyltransferases (PKMTs), has been linked to diverse biological and disease processes. The mono-methyltransferase SETD6 (SET-domain-containing protein 6) is a member of the PKMT family and was previously shown to regulate essential cellular processes such as the NF-κB, WNT and the oxidative stress pathways. However, on the biochemical level, little is known about the enzymatic mode of action of SETD6. Here we provide evidence that SETD6 forms high-molecular-weight structures. Specifically, we demonstrate that SETD6 monomeric, dimeric and trimeric forms are stabilized by the methyl donor, S -adenosyl-l -methionine. We then show that SETD6 has auto-methylation activity at K39 and K179, which serves as the major auto-methylation sites with a moderate auto-methylation activity toward K372. A point mutation at K179 but not at K39 and K372, located at the SET domain of SETD6, impaired SETD6 ability to form a trimer, strongly implying a link between the auto-methylation and the oligomerization state. Finally, by radioactive in vitro methylation experiments and biochemical kinetics analysis, we show that the auto-methylation at K39 and K179 increases the catalytic rate of SETD6. Collectively, our data support a model by which SETD6 auto-methylation and self-interaction positively regulate its enzymatic activity in vitro and may suggest that other PKMTs are regulated in the same manner. Graphical Abstract: Highlights: SETD6 forms monomers, dimers and trimers as well as higher-molecular-weight structures. SETD6 monomeric, dimeric and trimeric forms are stabilized by the methyl donor, S -adenosyl-l -methionine. K39 and K179 serve as the major auto-methylation sites of SETD6. SETD6 auto-methylation at K39 and K179 increases SETD6 enzymatic activity.