The muscle regulatory transcription factor MyoD participates with p53 to directly increase the expression of the pro-apoptotic Bcl2 family member PUMA

Abstract

The muscle regulatory transcription factor MyoD is a master regulator of skeletal myoblast differentiation. We have previously reported that MyoD is also necessary for the elevated expression of the pro-apoptotic Bcl2 family member PUMA, and the ensuing apoptosis, that occurs in a subset of myoblasts induced to differentiate. Herein, we report the identification of a functional MyoD binding site within the extended PUMA promoter. In silico analysis of the murine PUMA extended promoter revealed three potential MyoD binding sites within 2kb of the transcription start site. Expression from a luciferase reporter construct containing this 2kb fragment was enhanced by activation of MyoD in both myoblasts and fibroblasts and diminished by silencing of MyoD in myoblasts. Experiments utilizing truncated versions of this promoter region revealed that the potential binding site at position −857 was necessary for expression. Chromatin immunoprecipitation (ChIP) analysis confirmed binding of MyoD to the DNA region encompassing position −857. The increase in MyoD binding to the PUMA promoter as a consequence of culture in differentiation media (DM) was comparable to the increase in MyoD binding at the myogenin promoter and was diminished in myoblasts silenced for MyoD expression. Finally, ChIP analysis using an antibody specific for the transcription factor p53 demonstrated that, in myoblasts silenced for MyoD expression, p53 binding to the PUMA promoter was diminished in response to culture in DM. These data indicate that MyoD plays a direct role in regulating PUMA expression and reveal functional consequences of MyoD expression on p53 mediated transcription of PUMA.

A Structure-Guided Molecular Chaperone Approach for Restoring the Transcriptional Activity of the p53 Cancer Mutant Y220C

“…p53 levels were also upregulated upon PK9318 treatment. In addition, we observed significant upregulation of several apoptosis-related p53 downstream targets (e.g., BCL2 and CASP2 ), and MYOD1 , which has been shown to regulate PUMA expression [44]. p21 ( CDKN1A ) levels remained virtually the same in HUH-7 after PK9318 treatment.…”

Identification of the Myogenetic Oligodeoxynucleotides (myoDNs) That Promote Differentiation of Skeletal Muscle Myoblasts by Targeting Nucleolin

“…During myogenic differentiation, p53 cooperates with MyoD (Cerone et al, 2000 ) to activate transcription of retinoblastoma protein (Porrello et al, 2000 ), which serves as a cofactor of MyoD to arrest the cell cycle and facilitate muscle cell commitment (Gu et al, 1993 ; Novitch et al, 1996 ). A recent study revealed that p53 with MyoD coactivates the expression of the pro-apoptotic protein PUMA (Harford et al, 2017 ), which is required for the apoptosis associated with myoblast differentiation (Shaltouki et al, 2007 ; Harford et al, 2010 ). This accumulating evidence corroborates the findings that iSN04 upregulates p53 protein and induces myoblast differentiation.…”

Recurrent training rejuvenates and enhances transcriptome and methylome responses in young and older human muscle

“…The role of PPDPFL in muscular training adaptations is currently unknown. The other three genes, on the other hand, are known to be involved in apoptosis (BBC3, BCL2 Binding Component 3, also known as PUMA) 82 (MCL1, MCL1 Apoptosis Regulator, BCL2 Family Member) 83 and circadian clock-regulated physiological processes (e.g. muscle hypertrophy) (PER1, Period Circadian Regulator 1) 84 .…”