SETD3 protein is the actin-specific histidine N-methyltransferase

Abstract

Protein histidine methylation is a rare post-translational modification of unknown biochemical importance. In vertebrates, only a few methylhistidine-containing proteins have been reported, including β-actin as an essential example. The evolutionary conserved methylation of β-actin H73 is catalyzed by an as yet unknown histidine N-methyltransferase. We report here that the protein SETD3 is the actin-specific histidine N-methyltransferase. In vitro, recombinant rat and human SETD3 methylated β-actin at H73. Knocking-out SETD3 in both human HAP1 cells and in Drosophila melanogaster resulted in the absence of methylation at β-actin H73 in vivo, whereas β-actin from wildtype cells or flies was > 90% methylated. As a consequence, we show that Setd3-deficient HAP1 cells have less cellular F-actin and an increased glycolytic phenotype. In conclusion, by identifying SETD3 as the actin-specific histidine N-methyltransferase, our work pioneers new research into the possible role of this modification in health and disease and questions the substrate specificity of SET-domain-containing enzymes.

SETD2 is an actin lysine methyltransferase

“…In addition to our data demonstrating SETD2 acts on the actin cytoskeleton, the histone methyltransferase EZH2 has also been found to regulate actin polymerization through interaction with Vav1 and methylation of actin-associated Talin proteins 21,22 . More recently, it was reported that methylation of actin at histidine 73 is mediated by another SET domain-containing protein, the methyltransferase SETD3 16,23 . Whereas histidine methylation of actin has been known to regulate its dynamics for nearly two decades 24 , and Wilkinson et al 16 found SETD3 to be the only methyltransferase for this site, we show here that lysine methylation is a new regulatory PTM of actin.…”

SETD3 acts as a prognostic marker in breast cancer patients and modulates the viability and invasion of breast cancer cells

“…5C), indicating a possible defect in cytoskeletal function. As SETD3 is involved in cytoskeletal rearrangement 14 , which is implicated in migration and invasion 17 , we performed immunofluorescence microscopy employing the fluorescently labeled actin-binding protein phalloidin to study the consequence of SETD3 knockdown on cell morphology. In agreement with the invasion and collagen contraction assays, both cell morphology and the structure of actin filaments were altered when SETD3 was knocked down (Fig.…”

“…Methylation may, therefore, constitute a regulatory mechanism that does not only take place at the level of DNA expression. Recently, the SET Domain Containing 3, Actin Histidine Methyltransferase (SETD3) has been identified to be an actin-specific histidine N-methyltransferase 10,14 . SETD3 is a ubiquitously expressed protein, which is able to methylate the His73 position of actin in a physiologically relevant manner by using the co-factor S-adenosyl-methionine (SAM) as a methyl group donor 10 .…”

Molecular basis for histidine N3-specific methylation of actin H73 by SETD3

“…Previously, we have revealed the structural basis for histidine N1-specific methylation by human CARNMT1 3 . Recently, SET domain-containing protein 3 (SETD3) was identified as an N3-specific histidine methyltransferase of β-actin at the highly conserved residue H73 4,5 . Functionally, N3 methylation of H73 is associated with actin polymerization and ATP hydrolysis [6][7][8] , highlighting a role of histidine methylation in regulating cell motility.…”