Insulin increases phosphorylation of mitochondrial proteins in human skeletal muscle in vivo
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Insulin increases phosphorylation of mitochondrial proteins in human skeletal muscle in vivo. / Zhao, Xiaolu; Bak, Steffen; Pedersen, Andreas James Thestrup; Jensen, Ole Nørregaard; Højlund, Kurt.
I: Journal of Proteome Research, Bind 13, Nr. 5, 2014, s. 2359-2369.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Insulin increases phosphorylation of mitochondrial proteins in human skeletal muscle in vivo
AU - Zhao, Xiaolu
AU - Bak, Steffen
AU - Pedersen, Andreas James Thestrup
AU - Jensen, Ole Nørregaard
AU - Højlund, Kurt
N1 - CURIS 2014 NEXS 419
PY - 2014
Y1 - 2014
N2 - There is increasing evidence that multiple proteins involved in key regulatory processes in mitochondria are phosphorylated in mammalian tissues. Insulin regulates glucose metabolism by phosphorylation-dependent signaling and has been shown to stimulate ATP synthesis in human skeletal muscle. Here, we investigated the effect of insulin on the phosphorylation of mitochondrial proteins in human skeletal muscle in vivo. Using a combination of TiO2 phosphopeptide-enrichment, HILIC fractionation, and LC−MS/MS, we compared the phosphoproteomes of isolated mitochondria from skeletal muscle samples obtained from healthy individuals before and after 4 h of insulin infusion. In total, we identified 207 phosphorylation sites in 95 mitochondrial proteins. Of these phosphorylation sites, 45% were identified in both basal and insulin-stimulated samples. Insulin caused a 2-fold increase in the number of different mitochondrial phosphopeptides (87 ± 7 vs 40 ± 7, p = 0.015) and phosphoproteins (46 ± 2 vs 26 ± 3, p = 0.005) identified in each mitochondrial preparation. Almost half of the mitochondrial phosphorylation sites (n = 94) were exclusively identified in the insulin-stimulated state and included the majority of novel sites. Phosphorylation sites detected more often or exclusively in insulin-stimulated samples include multiple sites in mitochondrial proteins involved in oxidative phosphorylation, tricarboxylic acid cycle, and fatty acid metabolism, as well as several components of the newly defined mitochondrial inner membrane organizing system (MINOS). In conclusion, the present study demonstrates that insulin increases the phosphorylation of several mitochondrial proteins in human skeletal muscle in vivo and provides a first step in the understanding of how insulin potentially regulates mitochondrial processes by phosphorylation-dependent mechanisms.
AB - There is increasing evidence that multiple proteins involved in key regulatory processes in mitochondria are phosphorylated in mammalian tissues. Insulin regulates glucose metabolism by phosphorylation-dependent signaling and has been shown to stimulate ATP synthesis in human skeletal muscle. Here, we investigated the effect of insulin on the phosphorylation of mitochondrial proteins in human skeletal muscle in vivo. Using a combination of TiO2 phosphopeptide-enrichment, HILIC fractionation, and LC−MS/MS, we compared the phosphoproteomes of isolated mitochondria from skeletal muscle samples obtained from healthy individuals before and after 4 h of insulin infusion. In total, we identified 207 phosphorylation sites in 95 mitochondrial proteins. Of these phosphorylation sites, 45% were identified in both basal and insulin-stimulated samples. Insulin caused a 2-fold increase in the number of different mitochondrial phosphopeptides (87 ± 7 vs 40 ± 7, p = 0.015) and phosphoproteins (46 ± 2 vs 26 ± 3, p = 0.005) identified in each mitochondrial preparation. Almost half of the mitochondrial phosphorylation sites (n = 94) were exclusively identified in the insulin-stimulated state and included the majority of novel sites. Phosphorylation sites detected more often or exclusively in insulin-stimulated samples include multiple sites in mitochondrial proteins involved in oxidative phosphorylation, tricarboxylic acid cycle, and fatty acid metabolism, as well as several components of the newly defined mitochondrial inner membrane organizing system (MINOS). In conclusion, the present study demonstrates that insulin increases the phosphorylation of several mitochondrial proteins in human skeletal muscle in vivo and provides a first step in the understanding of how insulin potentially regulates mitochondrial processes by phosphorylation-dependent mechanisms.
U2 - 10.1021/pr401163t
DO - 10.1021/pr401163t
M3 - Journal article
C2 - 24641631
VL - 13
SP - 2359
EP - 2369
JO - Journal of Proteome Research
JF - Journal of Proteome Research
SN - 1535-3893
IS - 5
ER -
ID: 140387877