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HDAC4 regulates muscle fiber type-specific gene expression programs.

Cohen TJ, Choi MC, Kapur M, Lira VA, Yan Z, Yao TP - Mol. Cells (2015)

Bottom Line: The cytoplasmic localization is associated with HDAC4 hyper-phosphorylation in slow/oxidative-fibers.Genetic reprogramming of fast/glycolytic fibers to oxidative fibers by active CaMKII or calcineurin leads to increased HDAC4 phosphorylation, HDAC4 nuclear export, and an increase in markers associated with oxidative fibers.Thus differential phosphorylation and localization of HDAC4 contributes to establishing fiber type-specific transcriptional programs.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA.

ABSTRACT
Fiber type-specific programs controlled by the transcription factor MEF2 dictate muscle functionality. Here, we show that HDAC4, a potent MEF2 inhibitor, is predominantly localized to the nuclei in fast/glycolytic fibers in contrast to the sarcoplasm in slow/oxidative fibers. The cytoplasmic localization is associated with HDAC4 hyper-phosphorylation in slow/oxidative-fibers. Genetic reprogramming of fast/glycolytic fibers to oxidative fibers by active CaMKII or calcineurin leads to increased HDAC4 phosphorylation, HDAC4 nuclear export, and an increase in markers associated with oxidative fibers. Indeed, HDAC4 represses the MEF2-dependent, PGC-1α-mediated oxidative metabolic gene program. Thus differential phosphorylation and localization of HDAC4 contributes to establishing fiber type-specific transcriptional programs.

No MeSH data available.


Increased phosphorylation and cytoplasmic accumulation of HDAC4 by calcineurin or CaMKII activation. (A) Increased phosphorylation of HDAC4 was observed in calcineurin (CN) transgenic mouse muscles that acquired a fast-to-slow fiber type conversion. Muscles were collected from control and CN mice and muscle lysates from slow Sol and fast fibers including plantaris (PL), tibialis anterior (TA), and white vastus (WV) were analyzed by Western blot analysis with the indicated antibodies. (B) Increased HDAC4 phosphorylation at Ser-467 was confirmed by constitutively active CaMKII-T287D expression in Cos-7 cells. (C) Increased HDAC4 phosphorylation at Ser-467 correlated with expression of oxidative gene markers in TA muscle expressing CaMKII-T287D. Muscle lysates were subjected to Western blot analysis using the indicated antibodies. (D) Sub-cellular localization of HDAC4 and phospho-HDAC4 was determined by immunostaining analysis of frozen cross-sections from GFP-CaMKII-T287D-transfected TA muscles. The asterisk indicates CAMKII transfected fibers with peripheral HDAC4 accumulation similar to phospho-HDAC4. The arrowheads depict clear regions of membranous and cytoplasmic phospho-HDAC4 accumulation in CAMKII transfected fibers in contrast to neighboring untransfected fibers. Note the overall increased phosphorylation of HDAC4 with specific immunoreactivity along the muscle sarcolemmal membrane.
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f2-molce-38-4-343: Increased phosphorylation and cytoplasmic accumulation of HDAC4 by calcineurin or CaMKII activation. (A) Increased phosphorylation of HDAC4 was observed in calcineurin (CN) transgenic mouse muscles that acquired a fast-to-slow fiber type conversion. Muscles were collected from control and CN mice and muscle lysates from slow Sol and fast fibers including plantaris (PL), tibialis anterior (TA), and white vastus (WV) were analyzed by Western blot analysis with the indicated antibodies. (B) Increased HDAC4 phosphorylation at Ser-467 was confirmed by constitutively active CaMKII-T287D expression in Cos-7 cells. (C) Increased HDAC4 phosphorylation at Ser-467 correlated with expression of oxidative gene markers in TA muscle expressing CaMKII-T287D. Muscle lysates were subjected to Western blot analysis using the indicated antibodies. (D) Sub-cellular localization of HDAC4 and phospho-HDAC4 was determined by immunostaining analysis of frozen cross-sections from GFP-CaMKII-T287D-transfected TA muscles. The asterisk indicates CAMKII transfected fibers with peripheral HDAC4 accumulation similar to phospho-HDAC4. The arrowheads depict clear regions of membranous and cytoplasmic phospho-HDAC4 accumulation in CAMKII transfected fibers in contrast to neighboring untransfected fibers. Note the overall increased phosphorylation of HDAC4 with specific immunoreactivity along the muscle sarcolemmal membrane.

Mentions: To investigate if differential HDAC4 phosphorylation is a characteristic feature of different myofibers, we examined muscles from transgenic mice expressing a MCK-driven, constitutively-activated calcineurin (CN) transgene, which induces slow/ oxidative fiber formation in normally fast/glycolytic fiber-dominant muscles (Chin et al., 1998). As shown in Fig. 2A, while HDAC4 was more abundantly phosphorylated on S467, a target of CaMKII (Backs et al., 2006), in Sol muscle than in fast-type muscles in control mice, HDAC4 phosphorylation was markedly induced in all fast fibers analyzed, including plantaris (PL), tibialis anterior (TA), and white vastus (WV) muscle from CN-transgenic mice. This result indicates that HDAC4 phosphorylation positively correlates with the slow/oxidative fibers compared to fast/glycolytic fibers.


HDAC4 regulates muscle fiber type-specific gene expression programs.

Cohen TJ, Choi MC, Kapur M, Lira VA, Yan Z, Yao TP - Mol. Cells (2015)

Increased phosphorylation and cytoplasmic accumulation of HDAC4 by calcineurin or CaMKII activation. (A) Increased phosphorylation of HDAC4 was observed in calcineurin (CN) transgenic mouse muscles that acquired a fast-to-slow fiber type conversion. Muscles were collected from control and CN mice and muscle lysates from slow Sol and fast fibers including plantaris (PL), tibialis anterior (TA), and white vastus (WV) were analyzed by Western blot analysis with the indicated antibodies. (B) Increased HDAC4 phosphorylation at Ser-467 was confirmed by constitutively active CaMKII-T287D expression in Cos-7 cells. (C) Increased HDAC4 phosphorylation at Ser-467 correlated with expression of oxidative gene markers in TA muscle expressing CaMKII-T287D. Muscle lysates were subjected to Western blot analysis using the indicated antibodies. (D) Sub-cellular localization of HDAC4 and phospho-HDAC4 was determined by immunostaining analysis of frozen cross-sections from GFP-CaMKII-T287D-transfected TA muscles. The asterisk indicates CAMKII transfected fibers with peripheral HDAC4 accumulation similar to phospho-HDAC4. The arrowheads depict clear regions of membranous and cytoplasmic phospho-HDAC4 accumulation in CAMKII transfected fibers in contrast to neighboring untransfected fibers. Note the overall increased phosphorylation of HDAC4 with specific immunoreactivity along the muscle sarcolemmal membrane.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400309&req=5

f2-molce-38-4-343: Increased phosphorylation and cytoplasmic accumulation of HDAC4 by calcineurin or CaMKII activation. (A) Increased phosphorylation of HDAC4 was observed in calcineurin (CN) transgenic mouse muscles that acquired a fast-to-slow fiber type conversion. Muscles were collected from control and CN mice and muscle lysates from slow Sol and fast fibers including plantaris (PL), tibialis anterior (TA), and white vastus (WV) were analyzed by Western blot analysis with the indicated antibodies. (B) Increased HDAC4 phosphorylation at Ser-467 was confirmed by constitutively active CaMKII-T287D expression in Cos-7 cells. (C) Increased HDAC4 phosphorylation at Ser-467 correlated with expression of oxidative gene markers in TA muscle expressing CaMKII-T287D. Muscle lysates were subjected to Western blot analysis using the indicated antibodies. (D) Sub-cellular localization of HDAC4 and phospho-HDAC4 was determined by immunostaining analysis of frozen cross-sections from GFP-CaMKII-T287D-transfected TA muscles. The asterisk indicates CAMKII transfected fibers with peripheral HDAC4 accumulation similar to phospho-HDAC4. The arrowheads depict clear regions of membranous and cytoplasmic phospho-HDAC4 accumulation in CAMKII transfected fibers in contrast to neighboring untransfected fibers. Note the overall increased phosphorylation of HDAC4 with specific immunoreactivity along the muscle sarcolemmal membrane.
Mentions: To investigate if differential HDAC4 phosphorylation is a characteristic feature of different myofibers, we examined muscles from transgenic mice expressing a MCK-driven, constitutively-activated calcineurin (CN) transgene, which induces slow/ oxidative fiber formation in normally fast/glycolytic fiber-dominant muscles (Chin et al., 1998). As shown in Fig. 2A, while HDAC4 was more abundantly phosphorylated on S467, a target of CaMKII (Backs et al., 2006), in Sol muscle than in fast-type muscles in control mice, HDAC4 phosphorylation was markedly induced in all fast fibers analyzed, including plantaris (PL), tibialis anterior (TA), and white vastus (WV) muscle from CN-transgenic mice. This result indicates that HDAC4 phosphorylation positively correlates with the slow/oxidative fibers compared to fast/glycolytic fibers.

Bottom Line: The cytoplasmic localization is associated with HDAC4 hyper-phosphorylation in slow/oxidative-fibers.Genetic reprogramming of fast/glycolytic fibers to oxidative fibers by active CaMKII or calcineurin leads to increased HDAC4 phosphorylation, HDAC4 nuclear export, and an increase in markers associated with oxidative fibers.Thus differential phosphorylation and localization of HDAC4 contributes to establishing fiber type-specific transcriptional programs.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA.

ABSTRACT
Fiber type-specific programs controlled by the transcription factor MEF2 dictate muscle functionality. Here, we show that HDAC4, a potent MEF2 inhibitor, is predominantly localized to the nuclei in fast/glycolytic fibers in contrast to the sarcoplasm in slow/oxidative fibers. The cytoplasmic localization is associated with HDAC4 hyper-phosphorylation in slow/oxidative-fibers. Genetic reprogramming of fast/glycolytic fibers to oxidative fibers by active CaMKII or calcineurin leads to increased HDAC4 phosphorylation, HDAC4 nuclear export, and an increase in markers associated with oxidative fibers. Indeed, HDAC4 represses the MEF2-dependent, PGC-1α-mediated oxidative metabolic gene program. Thus differential phosphorylation and localization of HDAC4 contributes to establishing fiber type-specific transcriptional programs.

No MeSH data available.