DOC2B promotes insulin sensitivity in mice via a novel KLC1-dependent mechanism in skeletal muscle
dc.contributor.author | Zhang, Jing | |
dc.contributor.author | Oh, Eunjin | |
dc.contributor.author | Merz, Karla E. | |
dc.contributor.author | Aslamy, Arianne | |
dc.contributor.author | Veluthakal, Rajakrishnan | |
dc.contributor.author | Salunkhe, Vishal A. | |
dc.contributor.author | Ahn, Miwon | |
dc.contributor.author | Tunduguru, Ragadeepthi | |
dc.contributor.author | Thurmond, Debbie C. | |
dc.contributor.department | Cellular and Integrative Physiology, School of Medicine | en_US |
dc.date.accessioned | 2020-07-21T14:36:23Z | |
dc.date.available | 2020-07-21T14:36:23Z | |
dc.date.issued | 2019-05 | |
dc.description.abstract | Aims/hypothesis: Skeletal muscle accounts for >80% of insulin-stimulated glucose uptake; dysfunction of this process underlies insulin resistance and type 2 diabetes. Insulin sensitivity is impaired in mice deficient in the double C2 domain β (DOC2B) protein, while whole-body overexpression of DOC2B enhances insulin sensitivity. Whether insulin sensitivity in the skeletal muscle is affected directly by DOC2B or is secondary to an effect on other tissues is unknown; the underlying molecular mechanisms also remain unclear. Methods: Human skeletal muscle samples from non-diabetic or type 2 diabetic donors were evaluated for loss of DOC2B during diabetes development. For in vivo analysis, new doxycycline-inducible skeletal-muscle-specific Doc2b-overexpressing mice fed standard or high-fat diets were evaluated for insulin and glucose tolerance, and insulin-stimulated GLUT4 accumulation at the plasma membrane (PM). For in vitro analyses, a DOC2B-overexpressing L6-GLUT4-myc myoblast/myotube culture system was coupled with an insulin resistance paradigm. Biochemical and molecular biology methods such as site-directed mutagenesis, co-immunoprecipitation and mass spectrometry were used to identify the molecular mechanisms linking insulin stimulation to DOC2B. Results: We identified loss of DOC2B (55% reduction in RNA and 40% reduction in protein) in the skeletal muscle of human donors with type 2 diabetes. Furthermore, inducible enrichment of DOC2B in skeletal muscle of transgenic mice enhanced whole-body glucose tolerance (AUC decreased by 25% for female mice) and peripheral insulin sensitivity (area over the curve increased by 20% and 26% for female and male mice, respectively) in vivo, underpinned by enhanced insulin-stimulated GLUT4 accumulation at the PM. Moreover, DOC2B enrichment in skeletal muscle protected mice from high-fat-diet-induced peripheral insulin resistance, despite the persistence of obesity. In L6-GLUT4-myc myoblasts, DOC2B enrichment was sufficient to preserve normal insulin-stimulated GLUT4 accumulation at the PM in cells exposed to diabetogenic stimuli. We further identified that DOC2B is phosphorylated on insulin stimulation, enhancing its interaction with a microtubule motor protein, kinesin light chain 1 (KLC1). Mutation of Y301 in DOC2B blocked the insulin-stimulated phosphorylation of DOC2B and interaction with KLC1, and it blunted the ability of DOC2B to enhance insulin-stimulated GLUT4 accumulation at the PM. Conclusions/interpretation: These results suggest that DOC2B collaborates with KLC1 to regulate insulin-stimulated GLUT4 accumulation at the PM and regulates insulin sensitivity. Our observation provides a basis for pursuing DOC2B as a novel drug target in the muscle to prevent/treat type 2 diabetes. | en_US |
dc.eprint.version | Author's manuscript | en_US |
dc.identifier.citation | Zhang, J., Oh, E., Merz, K. E., Aslamy, A., Veluthakal, R., Salunkhe, V. A., Ahn, M., Tunduguru, R., & Thurmond, D. C. (2019). DOC2B promotes insulin sensitivity in mice via a novel KLC1-dependent mechanism in skeletal muscle. Diabetologia, 62(5), 845–859. https://doi.org/10.1007/s00125-019-4824-2 | en_US |
dc.identifier.uri | https://hdl.handle.net/1805/23288 | |
dc.language.iso | en_US | en_US |
dc.publisher | Springer Verlag | en_US |
dc.relation.isversionof | 10.1007/s00125-019-4824-2 | en_US |
dc.relation.journal | Diabetologia | en_US |
dc.rights | Publisher Policy | en_US |
dc.source | PMC | en_US |
dc.subject | DOC2B | en_US |
dc.subject | Glucose homeostasis | en_US |
dc.subject | GLUT4 | en_US |
dc.subject | Insulin sensitivity | en_US |
dc.subject | KLC1 | en_US |
dc.subject | Obesity | en_US |
dc.subject | Skeletal muscle | en_US |
dc.subject | Type 2 diabetes | en_US |
dc.title | DOC2B promotes insulin sensitivity in mice via a novel KLC1-dependent mechanism in skeletal muscle | en_US |
dc.type | Article | en_US |