Protein-tyrosine-phosphatase 1B activation is regulated developmentally in muscle of neonatal pigs

Suryawan, Agus; Davis, Teresa A.

doi:10.1152/ajpendo.00210.2002

Cited by 14 publications

(13 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, we conducted a detailed study of the role of development in the activation and protein abundance of these signaling components. We determined that the activation of PTP1B, PTEN, PP2A, and TSC2, all negative regulators of insulin signaling, are low in muscle of neonatal pigs and increase with age, consistent with a developmental decrease in the activation of the pathways that promote translation initiation (Suryawan and Davis, 2003;Suryawan et al, 2006). However, we were able to detect an effect of feeding only on TSC2 in which feeding decreased the activation of TSC2 and this effect of feeding was attenuated with age.…”

Section: Postnatal Ontogeny Of the Insulin And Amino Acid Signaling Pmentioning

confidence: 68%

Postnatal ontogeny of skeletal muscle protein synthesis in pigs1,2

Davis

Suryawan

Orellana

et al. 2008

Journal of Animal Science

View full text Add to dashboard Cite

The neonatal period is characterized by rapid growth and elevated rates of synthesis and accretion of skeletal muscle proteins. The fractional rate of muscle protein synthesis is very high at birth and declines rapidly with age. The elevated capacity for muscle protein synthesis in the neonatal pig is driven by the high ribosome content and, together with an increased efficiency of the translation process, promotes accelerated protein synthesis rates. Feeding profoundly stimulates muscle protein synthesis in neonatal pigs and the response decreases with age. The feeding-induced stimulation of muscle protein synthesis is modulated by an enhanced sensitivity to the postprandial increase in insulin and amino acids. The developmental decline in the response to insulin and amino acids parallels a marked decrease in the feeding-induced activation of translation initiation factors that regulate the binding of mRNA to the 40S ribosomal complex. The abundance and activation of many known positive regulators of the nutrient-and insulin-signaling pathways that are involved in translation initiation are high, whereas those of many negative regulators are low in skeletal muscle of younger pigs. Thus, the activation and(or) abundance of the positive regulators, such as the insulin receptor, insulin receptor-substrate-1, phosphoinositide-3 kinase, phosphoinositide-dependent kinase-1, protein kinase B, mammalian target of rapamycin, raptor, ribosomal protein S6 kinase-1, eukaryotic initiation factor (eIF) 4E-binding protein 1, and eIF4E associated with eIF4G, are greater in 7-d-old pigs than in 26-d-old pigs. The activation of negative regulators, including protein tyrosine phosphatase-1B, phosphatase and tensin homologue deleted on chromosome 10, protein phosphatase 2A, and tuberous sclerosis complex 1/2, are lower in 7-d-old pigs than in 26-d-old pigs. Thus, the developmental decline in the stimulation of skeletal muscle protein synthesis by insulin and amino acids is due in part to the developmentally related decrease in the activation of the signaling pathways that lead to translation initiation.

show abstract

Section: Postnatal Ontogeny Of the Insulin And Amino Acid Signaling Pmentioning

confidence: 68%

Postnatal ontogeny of skeletal muscle protein synthesis in pigs1,2

Davis

Suryawan

Orellana

et al. 2008

Journal of Animal Science

View full text Add to dashboard Cite

show abstract

“…These responses decrease with development in parallel with the decline in muscle protein synthesis (48,50,58). Furthermore, the activity of PTP1B, an inhibitor of the insulin-signaling pathway, increases with development, consistent with the developmental decline in insulin sensitivity during the early postnatal period (49). Here, we report a more detailed study of the role of development in the feeding-induced activation and protein abundance of signaling components that are upstream of mTOR, as well as downstream targets of mTOR, in skeletal muscle and liver of neonatal pigs.…”

mentioning

confidence: 60%

Developmental regulation of the activation of signaling components leading to translation initiation in skeletal muscle of neonatal pigs

Suryawan

Escobar²,

Frank³

et al. 2006

American Journal of Physiology-Endocrinology and Metabolism

Self Cite

View full text Add to dashboard Cite

The rapid growth of neonates is driven by high rates of skeletal muscle protein synthesis. This high rate of protein synthesis, which is induced by feeding, declines with development. Overnight-fasted 7- and 26-day-old pigs either remained fasted or were refed, and the abundance and phosphorylation of growth factor- and nutrient-induced signaling components that regulate mRNA translation initiation were measured in skeletal muscle and liver. In muscle, but not liver, the activation of inhibitors of protein synthesis, phosphatase and tensin homolog deleted on chromosome 10, protein phosphatase 2A, and tuberous sclerosis complex 1/2 increased with age. Serine/threonine phosphorylation of the insulin receptor and insulin receptor substrate-1, which downregulates insulin signaling, and the activation of AMP-activated protein kinase, an inhibitor of protein synthesis, were unaffected by age and feeding in muscle and liver. Activation of positive regulators of protein synthesis, mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase 1 (S6K1), and eIF4E-binding protein-1 (4E-BP1) decreased with age in muscle but not liver. Feeding enhanced mTOR, S6K1, and 4E-BP1 activation in muscle, and this response decreased with age. In liver, activation of S6K1 and 4E-BP1, but not mTOR, was increased by feeding but was unaffected by age. Raptor abundance and the association between raptor and mTOR were greater in 7- than in 26-day-old pigs. The results suggest that the developmental decline in skeletal muscle protein synthesis is due in part to developmental regulation of the activation of growth factor and nutrient-signaling components.

show abstract

“…We (37)(38)(39) have previously found that the activation of early steps in the insulin-signaling pathway upstream of PKB is induced by feeding. In this study, we investigated the separate effects of amino acids and insulin on the phosphorylation of PKB at Ser 473 , an important component of the insulin-signaling pathway (Fig.…”

Section: Resultsmentioning

confidence: 99%

Activation by insulin and amino acids of signaling components leading to translation initiation in skeletal muscle of neonatal pigs is developmentally regulated

Suryawan¹,

Orellana²,

Nguyen³

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

Self Cite

View full text Add to dashboard Cite

Insulin and amino acids act independently to stimulate protein synthesis in skeletal muscle of neonatal pigs, and the responses decrease with development. The purpose of this study was to compare the separate effects of fed levels of INS and AA on the activation of signaling components leading to translation initiation and how these responses change with development. Overnight-fasted 6- ( n = 4/group) and 26-day-old ( n = 6/ group) pigs were studied during 1) euinsulinemic-euglycemiceuaminoacidemic conditions (controls), 2) euinsulinemic-euglycemichyperaminoacidemic clamps (AA), and 3) hyperinsulinemic-euglycemic-euaminoacidemic clamps (INS). INS, but not AA, increased the phosphorylation of protein kinase B (PKB) and tuberous sclerosis 2 (TSC2). Both INS and AA increased protein synthesis and the phosphorylation of mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase-1, and eukaryotic initiation factor (eIF)4E-binding protein 1 (4E-BP1), and these responses were higher in 6-day-old compared with 26-day-old pigs. Both INS and AA decreased the binding of 4E-BP1 to eIF4E and increased eIF4E binding to eIF4G; these effects were greater in 6-day-old than in 26-day-old pigs. Neither INS nor AA altered the composition of mTORC1 (raptor, mTOR, and GβL) or mTORC2 (rictor, mTOR, and GβL) complexes. Furthermore, neither INS, AA, nor age had any effect on the abundance of Rheb and the phosphorylation of AMP-activated protein kinase and eukaryotic elongation factor 2. Our results suggest that the activation by insulin and amino acids of signaling components leading to translation initiation is developmentally regulated and parallels the developmental decline in protein synthesis in skeletal muscle of neonatal pigs.

show abstract

Protein-tyrosine-phosphatase 1B activation is regulated developmentally in muscle of neonatal pigs

Cited by 14 publications

References 49 publications

Postnatal ontogeny of skeletal muscle protein synthesis in pigs1,2

Postnatal ontogeny of skeletal muscle protein synthesis in pigs1,2

Developmental regulation of the activation of signaling components leading to translation initiation in skeletal muscle of neonatal pigs

Activation by insulin and amino acids of signaling components leading to translation initiation in skeletal muscle of neonatal pigs is developmentally regulated

Contact Info

Product

Resources

About