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Biochemistry, Biophysics, and Structural Biology Commons

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Physiology

Insulin

University of Massachusetts Medical School

Articles 1 - 3 of 3

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Systemic Insulin Sensitivity Is Regulated By Gps2 Inhibition Of Akt Ubiquitination And Activation In Adipose Tissue, Carly T. Cederquist, Claudia Lentucci, Camila Martinez Calejman, Vanessa Hayashi, Joseph Orofino, David A. Guertin, Susan K. Fried, Mi-Jeong Lee, M. Dafne Cardamone, Valentina Perissi Jan 2017

Systemic Insulin Sensitivity Is Regulated By Gps2 Inhibition Of Akt Ubiquitination And Activation In Adipose Tissue, Carly T. Cederquist, Claudia Lentucci, Camila Martinez Calejman, Vanessa Hayashi, Joseph Orofino, David A. Guertin, Susan K. Fried, Mi-Jeong Lee, M. Dafne Cardamone, Valentina Perissi

Open Access Articles

OBJECTIVE: Insulin signaling plays a unique role in the regulation of energy homeostasis and the impairment of insulin action is associated with altered lipid metabolism, obesity, and Type 2 Diabetes. The main aim of this study was to provide further insight into the regulatory mechanisms governing the insulin signaling pathway by investigating the role of non-proteolytic ubiquitination in insulin-mediated activation of AKT.

METHODS: The molecular mechanism of AKT regulation through ubiquitination is first dissected in vitro in 3T3-L1 preadipocytes and then validated in vivo using mice with adipo-specific deletion of GPS2, an endogenous inhibitor of Ubc13 activity (GPS2-AKO mice).

RESULTS ...


Protein Kinase Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (Map4k4) Promotes Obesity-Induced Hyperinsulinemia, Rachel J. Roth Flach, Laura V. Danai, Marina Distefano, Mark Kelly, Lorena Garcia Menendez, Agata Jurczyk, Rohit B. Sharma, Dae Young Jung, Jong Hun Kim, Jason K. Kim, Rita Bortell, Laura C. Alonso, Michael P. Czech Jul 2016

Protein Kinase Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (Map4k4) Promotes Obesity-Induced Hyperinsulinemia, Rachel J. Roth Flach, Laura V. Danai, Marina Distefano, Mark Kelly, Lorena Garcia Menendez, Agata Jurczyk, Rohit B. Sharma, Dae Young Jung, Jong Hun Kim, Jason K. Kim, Rita Bortell, Laura C. Alonso, Michael P. Czech

Open Access Articles

Previous studies revealed a paradox whereby mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) acted as a negative regulator of insulin sensitivity in chronically obese mice, yet systemic deletion of Map4k4 did not improve glucose tolerance. Here, we report markedly reduced glucose-responsive plasma insulin and C-peptide levels in whole body Map4k4-depleted mice (M4K4 iKO) as well as an impaired first phase of insulin secretion from islets derived from M4K4 iKO mice ex vivo After long-term high fat diet (HFD), M4K4 iKO mice pancreata also displayed reduced beta cell mass, fewer proliferating beta cells and reduced islet-specific gene mRNA expression compared ...


Role Of Protein Kinase Map4k4 In Energy Metabolism: A Dissertation, Laura V. Danai Apr 2015

Role Of Protein Kinase Map4k4 In Energy Metabolism: A Dissertation, Laura V. Danai

GSBS Dissertations and Theses

Systemic glucose regulation is essential for human survival as low or chronically high glucose levels can be detrimental to the health of an individual. Glucose levels are highly regulated via inter-organ communication networks that alter metabolic function to maintain euglycemia. For example, when nutrient levels are low, pancreatic α-cells secrete glucagon, which signals to the liver to promote glycogen breakdown and glucose production. In times of excess nutrient intake, pancreatic β-cells release insulin. Insulin signals to the liver to suppress hepatic glucose production, and signals to the adipose tissue and the skeletal muscle to take up excess glucose via insulin-regulated ...