Garcia-Roves 2008 J Biol Chem: Difference between revisions
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|authors=Garcia-Roves PM, Osler ME, Holmstroem MH, Zierath JR | |authors=Garcia-Roves PM, Osler ME, Holmstroem MH, Zierath JR | ||
|year=2008 | |year=2008 | ||
|journal= | |journal=J. Biol. Chem. | ||
|abstract=AMP-activated protein kinase (AMPK) is a heterotrimeric complex, composed of a catalytic subunit (Ξ±) and two regulatory subunits (Ξ² and Ξ³), that works as a cellular energy sensor. The existence of multiple heterotrimeric complexes provides a molecular basis for the multiple roles of this highly conserved signaling system. The AMPK<sub>Ξ³3</sub> subunit is predominantly expressed in skeletal muscle, mostly in type II glycolytic fiber types. We determined whether the AMPK<sub>Ξ³3</sub> subunit has a role in signaling pathways that mediate mitochondrial biogenesis in skeletal muscle. We provide evidence that overexpression or ablation of the AMPK<sub>Ξ³3</sub> subunit does not appear to play a critical role in defining mitochondrial content in resting skeletal muscle. However, overexpression of a mutant form (R225Q) of the AMPK<sub>Ξ³3</sub> subunit (Tg-AMPK<sub>Ξ³3</sub><sup>225Q</sup>) increases mitochondrial biogenesis in glycolytic skeletal muscle. These adaptations are associated with an increase in expression of the co-activator PGC-1Ξ± and several transcription factors that regulate mitochondrial biogenesis, including NRF-1, NRF-2, and TFAM. Succinate dehydrogenase staining, a marker of the oxidative profile of individual fibers, was also increased in transversal skeletal muscle sections of white gastrocnemius muscle from Tg-AMPK<sub>Ξ³3</sub><sup>225Q</sup> mice, independent of changes in fiber type composition. In conclusion, a single nucleotide mutation (R225Q) in the AMPK gamma3 subunit is associated with mitochondrial biogenesis in glycolytic skeletal muscle, concomitant with increased expression of the co-activator PGC-1Ξ± and several transcription factors that regulate mitochondrial proteins, without altering fiber type composition. | |abstract=AMP-activated protein kinase (AMPK) is a heterotrimeric complex, composed of a catalytic subunit (Ξ±) and two regulatory subunits (Ξ² and Ξ³), that works as a cellular energy sensor. The existence of multiple heterotrimeric complexes provides a molecular basis for the multiple roles of this highly conserved signaling system. The AMPK<sub>Ξ³3</sub> subunit is predominantly expressed in skeletal muscle, mostly in type II glycolytic fiber types. We determined whether the AMPK<sub>Ξ³3</sub> subunit has a role in signaling pathways that mediate mitochondrial biogenesis in skeletal muscle. We provide evidence that overexpression or ablation of the AMPK<sub>Ξ³3</sub> subunit does not appear to play a critical role in defining mitochondrial content in resting skeletal muscle. However, overexpression of a mutant form (R225Q) of the AMPK<sub>Ξ³3</sub> subunit (Tg-AMPK<sub>Ξ³3</sub><sup>225Q</sup>) increases mitochondrial biogenesis in glycolytic skeletal muscle. These adaptations are associated with an increase in expression of the co-activator PGC-1Ξ± and several transcription factors that regulate mitochondrial biogenesis, including NRF-1, NRF-2, and TFAM. Succinate dehydrogenase staining, a marker of the oxidative profile of individual fibers, was also increased in transversal skeletal muscle sections of white gastrocnemius muscle from Tg-AMPK<sub>Ξ³3</sub><sup>225Q</sup> mice, independent of changes in fiber type composition. In conclusion, a single nucleotide mutation (R225Q) in the AMPK gamma3 subunit is associated with mitochondrial biogenesis in glycolytic skeletal muscle, concomitant with increased expression of the co-activator PGC-1Ξ± and several transcription factors that regulate mitochondrial proteins, without altering fiber type composition. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/18838377 PMID: 18838377] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/18838377 PMID: 18838377] | ||
Revision as of 14:07, 14 October 2010
| Garcia-Roves PM, Osler ME, HolmstrΓΆm MH, Zierath JR (2008) Gain-of-function R225Q mutation in AMP-activated protein kinase gamma3 subunit increases mitochondrial biogenesis in glycolytic skeletal muscle. J. Biol. Chem. 283: 35724-25734. |
Β» [[Has info::PMID: 18838377]]
Garcia-Roves PM, Osler ME, Holmstroem MH, Zierath JR (2008) J. Biol. Chem.
Abstract: AMP-activated protein kinase (AMPK) is a heterotrimeric complex, composed of a catalytic subunit (Ξ±) and two regulatory subunits (Ξ² and Ξ³), that works as a cellular energy sensor. The existence of multiple heterotrimeric complexes provides a molecular basis for the multiple roles of this highly conserved signaling system. The AMPKΞ³3 subunit is predominantly expressed in skeletal muscle, mostly in type II glycolytic fiber types. We determined whether the AMPKΞ³3 subunit has a role in signaling pathways that mediate mitochondrial biogenesis in skeletal muscle. We provide evidence that overexpression or ablation of the AMPKΞ³3 subunit does not appear to play a critical role in defining mitochondrial content in resting skeletal muscle. However, overexpression of a mutant form (R225Q) of the AMPKΞ³3 subunit (Tg-AMPKΞ³3225Q) increases mitochondrial biogenesis in glycolytic skeletal muscle. These adaptations are associated with an increase in expression of the co-activator PGC-1Ξ± and several transcription factors that regulate mitochondrial biogenesis, including NRF-1, NRF-2, and TFAM. Succinate dehydrogenase staining, a marker of the oxidative profile of individual fibers, was also increased in transversal skeletal muscle sections of white gastrocnemius muscle from Tg-AMPKΞ³3225Q mice, independent of changes in fiber type composition. In conclusion, a single nucleotide mutation (R225Q) in the AMPK gamma3 subunit is associated with mitochondrial biogenesis in glycolytic skeletal muscle, concomitant with increased expression of the co-activator PGC-1Ξ± and several transcription factors that regulate mitochondrial proteins, without altering fiber type composition.
Labels:
Stress:Genetic Defect; Knockdown; Overexpression
Tissue;cell: Skeletal Muscle
Regulation: Respiration; OXPHOS; ETS Capacity, Mitochondrial Biogenesis; Mitochondrial Density
HRR: Oxygraph-2k, Method
