An actin-WHAMM interaction linking SETD2 and autophagy

• Published in: Biochemical and biophysical research communications Vol. 558; pp. 202 - 208
• Main Authors: Seervai, Riyad N.H., Grimm, Sandra L., Jangid, Rahul K., Tripathi, Durga Nand, Coarfa, Cristian, Walker, Cheryl Lyn
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 18.06.2021
• Subjects: Actin; Actins - metabolism; Autophagy; Autophagy - genetics; Autophagy - physiology; Autophagy-Related Proteins - genetics; Autophagy-Related Proteins - metabolism; Carcinoma, Renal Cell - genetics; Carcinoma, Renal Cell - metabolism; Carcinoma, Renal Cell - pathology; Cell Line; Cell Line, Tumor; Down-Regulation; Gene Knockout Techniques; Histone-Lysine N-Methyltransferase - deficiency; Histone-Lysine N-Methyltransferase - genetics; Histone-Lysine N-Methyltransferase - metabolism; Humans; Kidney Neoplasms - genetics; Kidney Neoplasms - metabolism; Kidney Neoplasms - pathology; Membrane Proteins - metabolism; Microtubule-Associated Proteins - metabolism; Renal cell carcinoma; SETD2; WHAMM; SETD2; ccRCC; ARP2/3; ATG; Renal cell carcinoma; Actin; NPF; WHAMM; VHL; Autophagy; MAP1LC3
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2020.09.025

The process of autophagy is dysregulated in many cancers including clear cell renal cell carcinoma (ccRCC). Autophagy involves the coordination of numerous autophagy-related (ATG) genes, as well as processes involving the actin cytoskeleton. The histone methyltransferase SETD2, frequently inactivated in ccRCC, has recently been shown to also methylate cytoskeletal proteins, which in the case of actin lysine 68 trimethylation (ActK68me3) regulates actin polymerization dynamics. Here we show that cells lacking SETD2 exhibit autophagy defects, as well as decreased interaction of the actin nucleation promoting factor WHAMM with its target actin, which is required for initiation of autophagy. Interestingly, the WHAMM actin binding deficit could be rescued with pharmacologic induction of actin polymerization in SETD2-null cells using Jasplakinolide. These data indicate that the decreased interaction between WHAMM and its target actin in SETD2-null cells was secondary to altered actin dynamics rather than loss of the SETD2 ActK68me3 mark itself, and underscores the importance of the functional defect in actin polymerization in SETD2-null cells exhibiting autophagy defects. SETD2 trimethylates histone H3 at lysine 36 (H3K36me3) to affect expression and alternative splicing of ATG12. Additionally, SETD2 trimethylation of actin at lysine 68 (ActK68me3) regulates actin polymerization, which in turn regulates the interaction between actin and WHAMM. Loss of SETD2 inhibits the actin-WHAMM interaction, which could be restored by induction of actin polymerization in these cells. [Display omitted] •Loss of SETD2 results in defects in autophagic flux.•SETD2 deletion does not affect transcriptional regulation of autophagy-related genes.•WHAMM expression and interaction with actin is altered in SETD2-null 786–0 cells.•This altered actin-WHAMM interaction results from defective actin polymerization.