Track topics on Twitter Track topics that are important to you
Sterol regulatory element-binding protein (SREBP), a highly conserved family of membrane-bound transcription factors, is an essential regulator for cellular cholesterol and lipid homeostasis in mammalian cells. Sre1, the homolog of SREBP in the fission yeast Schizosaccharomyces pombe (S. pombe), regulates genes involved in the transcriptional responses to low sterol as well as low oxygen. Previous study reported that casein kinase 1 family member Hhp2 phosphorylated the Sre1 N-terminal transcriptional factor domain (Sre1N) and accelerated Sre1N degradation, and other kinases might exist for regulating the Sre1 function. To gain insight into the mechanisms underlying the Sre1 activity and to identify additional kinases involved in regulation of Sre1 function, we developed a luciferase reporter system to monitor the Sre1 activity through its binding site called SRE2 in living yeast cells. Here we showed that both ergosterol biosynthesis inhibitors and hypoxia-mimic CoCl2 caused a dose-dependent increase in the Sre1 transcription activity, concurrently, these induced transcription activities were almost abolished in Δsre1 cells. Surprisingly, either AMPKα Subunit Ssp2 deletion or Glycogen Synthase Kinases Gsk3/Gsk31 double deletion significantly suppressed ergosterol biosynthesis inhibitors- or CoCl2-induced Sre1 activity. Notably, the Δssp2Δgsk3Δgsk31 mutant showed further decreased Sre1 activity when compared with their single or double deletion. Consistently, the Δssp2Δgsk3Δgsk31 mutant showed more marked temperature sensitivity than any of their single or double deletion. Moreover, the fluorescence of GFP-Sre1N localized at the nucleus in wild-type cells, but significantly weaker nuclear fluorescence of GFP-Sre1N was observed in Δssp2, Δgsk3Δgsk31, Δssp2Δgsk3, Δssp2Δgsk31 or Δssp2Δgsk3Δgsk31 cells. On the other hand, the immunoblot showed a dramatic decrease in GST-Sre1N levels in the Δgsk3Δgsk31 or the Δssp2Δgsk3Δgsk31 cells but not in the Δssp2 cells. Altogether, our findings suggest that Gsk3/Gsk31 may regulate Sre1N degradation, while Ssp2 may regulate not only the degradation of Sre1N but also its translocation to the nucleus.
This article was published in the following journal.
Name: PloS one
Insulin-stimulated hepatic glycogen synthesis is central to glucose homeostasis. Here, we show that PPP1R3G, a regulatory subunit of protein phosphatase 1 (PP1), is directly phosphorylated by AKT. PPP...
Alzheimer's disease (AD) is the most common form of neurodegenerative disorder with dementia, accounting for approximately 70% of the all cases. Currently, 5.8 million people in the U.S. are living wi...
Glycogen synthase kinase-3β (GSK3β) is a serine/threonine kinase involved in the regulation of embryonic development, glycogen metabolism, protein synthesis, mitosis, and apoptosis. To understand th...
The ventral hippocampus is a component of the neural circuitry involved with context-associated memory for reward and generation of appropriate behavioral responses to context. Glycogen synthase kinas...
Islet inflammation is associated with defective β cell function and mass in type 2 diabetes (T2D). Glycogen Synthase Kinase 3β (GSK3β) has been identified as an important regulator of inflammation ...
The project is designed to generate critical information to design and justify a robust trial on lithium prevention of the onset of Alzheimer's disease (AD). Lithium exerts and inhibitory ...
The purpose of this study is to evaluate if 4 escalating doses during 20 weeks of NP031112 are safe and tolerated in patients with Alzheimer´s disease.
Glycogen, is the storage form of glucose. It is usually formed from sugar and stored in the liver. When tissues, such as muscle, need glucose for fuel the stored glycogen is converted in...
Metformin, a traditional antidiabetic medication, exerts glucose lowering effects by activating AMP-activated protein kinase (AMPK), a critical enzyme involved in the lipid and glucose met...
Progressive Supranuclear Palsy (PSP) is a relentlessly progressive neurodegenerative disorder, clinically characterized by parkinsonism with prominent axial involvement and postural instab...
A class of protein-serine-threonine kinases that was originally found as one of the three types of kinases that phosphorylate GLYCOGEN SYNTHASE. Glycogen synthase kinases along with CA(2+)-CALMODULIN DEPENDENT PROTEIN KINASES and CYCLIC AMP-DEPENDENT PROTEIN KINASES regulate glycogen synthase activity.
An enzyme that catalyzes the conversion of phosphorylated, inactive glycogen synthase D to active dephosphoglycogen synthase I. EC 220.127.116.11.
A glycogen synthase kinase that was originally described as a key enzyme involved in glycogen metabolism. It regulates a diverse array of functions such as CELL DIVISION, microtubule function and APOPTOSIS.
A glycogen synthase kinase-3 type enzyme that functions in ENERGY METABOLISM; EMBRYONIC DEVELOPMENT; and NEUROGENESIS. It is also involved in PROTEIN BIOSYNTHESIS and regulates cell growth and proliferation as a component of the WNT SIGNALING PATHWAY and other signaling pathways. Certain polymorphisms in the GSK3B gene have been associated with PARKINSON DISEASE; ALZHEIMER DISEASE; and BIPOLAR DISORDER.
A CALMODULIN-dependent enzyme that catalyzes the phosphorylation of proteins. This enzyme is also sometimes dependent on CALCIUM. A wide range of proteins can act as acceptor, including VIMENTIN; SYNAPSINS; GLYCOGEN SYNTHASE; MYOSIN LIGHT CHAINS; and the MICROTUBULE-ASSOCIATED PROTEINS. (From Enzyme Nomenclature, 1992, p277)
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...