CREB, NF-Y and MEIS1 conserved binding sites are essential to balance Myostatin promoter/enhancer activity during early myogenesis

Abstract

Myostatin (MSTN) is a strong inhibitor of skeletal muscle growth in human and other vertebrates. Its transcription is controlled by a proximal promoter/enhancer (Mstn P/E) containing a TATA box besides CREB, NF-Y, MEIS1 and FXR transcription factor binding sites (TFBSs), which are conserved throughout evolution. The aim of this work was to investigate the role of these TFBSs on Mstn P/E activity and evaluate the potential of their putative ligands as Mstn trans regulators. Mstn P/E mutant constructs were used to establish the role of conserved TFBSs using dual-luciferase assays. Expression analyses were performed by RT-PCR and in situ hybridization in C2C12 myoblasts and E10.5 mouse embryos, respectively. Our results revealed that CREB, NF-Y and MEIS1 sites are required to balance Mstn P/E activity, keeping Mstn transcription within basal levels during myoblast proliferation. Furthermore, our data showed that NF-Y site is essential, although not sufficient, to mediate Mstn P/E transcriptional activity. In turn, CREB and MEIS1 binding sites seem to depend on the presence of NF-Y site to induce Mstn P/E. FXR appears not to confer any effect on Mstn P/E activity, except in the absence of all other conserved TFBS. Accordingly, expression studies pointed to CREB, NF-Y and MEIS1 but not to FXR factors as possible regulators of Mstn transcription in the myogenic context. Altogether, our findings indicated that CREB, NF-Y and MEIS1 conserved sites are essential to control basal Mstn transcription during early myogenesis, possibly by interacting with these or other related factors.

Target Gene Prediction of Transcription Factor Using a New Neighborhood-regularized Tri-factorization One-class Collaborative Filtering Algorithm

“…The direct association between CREM and MEIS1 was not known although they are involved in the myogenesis, the growth of skeletal muscle. A recent study suggests that although CREM and MEIS1 may not directly interact, they seem to regulate the growth process through another transcription factor, NF-Y [65]. A recent ChIP-seq experiment showed that RUNX1 is a target of AR, which is important for AR-dependent transcription and cell growth in androgen-dependent prostate cancer [66].…”

Decoding the transcriptome of denervated muscle at single-nucleus resolution

“…The effects of other regulons in the pathogenesis of muscle atrophy remain unidentified. Robo2 and Meis1 are known to be essential for embryonic skeletal muscle development [22, 44]; activation of their regulons in denervation implicates activation of an early developmental program in the pathogenesis of muscle atrophy. Bhlhe40 has been shown to control oxidative metabolism in myogenic cells [45], while Elk4 has been reported to be a target gene downstream of MAPKs.…”

Myostatin gene promoter: structure, conservation and importance as a target for muscle modulation

“…Lastly, it is relevant to mention that besides the promoter, several other regulators are also important for the proper functioning of MSTN gene and protein. The role of several transcription factors [28], epigenetic regulators, post-transcriptional [14], and post-translational [9, 108, 109] controllers are slowly being unravelled and it is becoming clear that a complex network of elements is necessary to determine the moment and place MSTN should act in several physiological contexts.…”

“…In fact, several potential NFAT binding sites were identified in the mouse Mstn promoter [26]. A binding site for CREB was found in the Mstn promoter [25] and deletion constructs have indicated that CREB, together with NF-Y and MEIS1 binding sites, are essential for the basal control of Mstn transcription during early myogenesis [28]. Furthermore, IGF-I-mediated promoter activation was disrupted by cotransfection of CREB siRNA vectors, indicating a possible correlation between IGF-I signaling and CREB [27].…”