MESH1 knockdown triggers proliferation arrest through TAZ repression

• Authors: Tianai Sun, Duke University; Chien-Kuang Cornelia Ding, Duke University; Yuning Zhang, Duke University; Yang Zhang, Duke University; Chao-Chieh Lin, Duke University; Jianli Wu, Duke University; Yasaman Setayeshpour, Duke University; Si’Ana Coggins, Emory University; Caitlin Shepard, Emory University; Everardo Macias, Duke University; Baek Kim, Emory University; Pei Zhou, Duke University; Raluca Gordân, Duke University; Jen-Tsan Chi, Duke University
• Journal Title: CELL DEATH & DISEASE
• Volume: Volume 13, Number 3
• Publisher: SPRINGERNATURE | 2022-03-10, Pages 221-221
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1038/s41419-022-04663-6
• Subjects: Health Sciences, Pathology; Chemistry, Biochemistry
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cell Biology; HISTONE DEACETYLASES; HIPPO PATHWAY; STEM-CELL; YAP; GROWTH; EFFECTORS; (P)PPGPP; YAP/TAZ

Abstract

All organisms are constantly exposed to various stresses, necessitating adaptive strategies for survival. In bacteria, the main stress-coping mechanism is the stringent response triggered by the accumulation of “alarmone” (p)ppGpp to arrest proliferation and reprogram transcriptome. While mammalian genomes encode MESH1—the homolog of the (p)ppGpp hydrolase SpoT, current knowledge about its function remains limited. We found MESH1 expression tended to be higher in tumors and associated with poor patient outcomes. Consistently, MESH1 knockdown robustly inhibited proliferation, depleted dNTPs, reduced tumor sphere formation, and retarded xenograft growth. These antitumor phenotypes associated with MESH1 knockdown were accompanied by a significantly altered transcriptome, including the repressed expression of TAZ, a HIPPO coactivator, and proliferative gene. Importantly, TAZ restoration mitigated many anti-growth phenotypes of MESH1 knockdown, including proliferation arrest, reduced sphere formation, tumor growth inhibition, dNTP depletion, and transcriptional changes. Furthermore, TAZ repression was associated with the histone hypo-acetylation at TAZ regulatory loci due to the induction of epigenetic repressors HDAC5 and AHRR. Together, MESH1 knockdown in human cells altered the genome-wide transcriptional patterns and arrested proliferation that mimicked the bacterial stringent response through the epigenetic repression of TAZ expression.