Previous studies showed that insulin antagonizes AMP-activated protein kinase activation by ischemia and that protein kinase B might be implicated. Here we investigated whether the direct phosphorylation of AMP-activated protein kinase by protein kinase B might participate in this effect. Protein kinase B phosphorylated recombinant bacterially expressed AMP-activated protein kinase heterotrimers at Ser(485) of the alpha1-subunits. In perfused rat hearts, phosphorylation of the alpha1/alpha2 AMP-activated protein kinase subunits on Ser(485)/Ser(491) was increased by insulin and insulin pretreatment decreased the phosphorylation of the alpha-subunits at Thr(172) in a subsequent ischemic episode. It is proposed that the effect of insulin to antagonize AMP-activated protein kinase activation involves a hierarchical mechanism whereby Ser(485)/Ser(491) phosphorylation by protein kinase B reduces subsequent phosphorylation of Thr(172) by LKB1 and the resulting activation of AMP-activated protein kinase.
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http://dx.doi.org/10.1074/jbc.M506850200 | DOI Listing |
Hepatology
January 2025
Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA.
Background Aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) affects about a third of adults worldwide and is projected soon to be the leading cause of cirrhosis. It occurs when fat accumulates in hepatocytes and can progress to metabolic dysfunction-associated steatohepatitis (MASH), liver cirrhosis, and hepatocellular carcinoma. MASLD pathogenesis is believed to involve a combination of genetic and environmental risk factors.
View Article and Find Full Text PDFJ Appl Oral Sci
January 2025
Ningde Hospital Affiliated to Ningde Normal University, Department of Stomatology, Fujian, China.
Objective: This study aimed to investigate the role of transmembrane emp24 domain-containing protein 2 (TMED2) in oral squamous cell carcinoma (OSCC).
Methodology: A bioinformatics analysis was first conducted to explore TMED2 expression in OSCC and its relation with overall survival. The analysis results were further verified by assessing TMED2 expression levels in human normal oral keratinocyte cells and human OSCC cell lines using quantitative real-time polymerase chain reaction and the Western blot.
Sci Adv
January 2025
Key Laboratory of Plant Carbon Capture, Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Plants sense and respond to hyperosmotic stress via quick activation of sucrose nonfermenting 1-related protein kinase 2 (SnRK2). Under unstressed conditions, the protein phosphatase type 2C (PP2C) in clade A interact with and inhibit SnRK2s in subgroup III, which are released from the PP2C inhibition via pyrabactin resistance 1-like (PYL) abscisic acid receptors. However, how SnRK2s are released under osmotic stress is unclear.
View Article and Find Full Text PDFJ Med Chem
January 2025
Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 East Montview Boulevard, Aurora, Colorado 80045, United States.
AMP-activated protein kinase (AMPK) is a central mediator of cellular metabolism and is activated in direct response to low ATP levels. Activated AMPK inhibits anabolic pathways and promotes catabolic activities that generate ATP through the phosphorylation of multiple target substrates. AMPK is a therapeutic target for activation in several chronic metabolic diseases, and there is increasing interest in targeting AMPK activity in cancer where it can act as a tumor suppressor or conversely it can support cancer cell survival.
View Article and Find Full Text PDFPLoS One
January 2025
Precision Laboratory of Vascular Medicine, Shanxi Cardiovascular Hospital Affiliated Shanxi Medical University, Taiyuan, PR China.
Background: Myocardial ischemia-reperfusion injury (MIRI) is an important complication in the treatment of heart failure, and its treatment has not made satisfactory progress. Nitroxyl (HNO) showed protective effects on the heart failure, however, the effect and underlying mechanism of HNO on MIRI remain largely unclear.
Methods: MIRI model in this study was established to induce H9C2 cell injury through hypoxia/reoxygenation (H/R) in vitro.
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