| First Author | Li C | Year | 2024 |
| Journal | J Biol Chem | Volume | 300 |
| Issue | 5 | Pages | 107254 |
| PubMed ID | 38569934 | Mgi Jnum | J:347982 |
| Mgi Id | MGI:7639012 | Doi | 10.1016/j.jbc.2024.107254 |
| Citation | Li C, et al. (2024) Nesprin-2 is a novel scaffold protein for telethonin and FHL-2 in the cardiomyocyte sarcomere. J Biol Chem 300(5):107254 |
| abstractText | Nesprins comprise a family of multi-isomeric scaffolding proteins, forming the linker of nucleoskeleton-and-cytoskeleton complex with lamin A/C, emerin and SUN1/2 at the nuclear envelope. Mutations in nesprin-1/-2 are associated with Emery-Dreifuss muscular dystrophy (EDMD) with conduction defects and dilated cardiomyopathy (DCM). We have previously observed sarcomeric staining of nesprin-1/-2 in cardiac and skeletal muscle, but nesprin function in this compartment remains unknown. In this study, we show that specific nesprin-2 isoforms are highly expressed in cardiac muscle and localize to the Z-disc and I band of the sarcomere. Expression of GFP-tagged nesprin-2 giant spectrin repeats 52 to 53, localized to the sarcomere of neonatal rat cardiomyocytes. Yeast two-hybrid screening of a cardiac muscle cDNA library identified telethonin and four-and-half LIM domain (FHL)-2 as potential nesprin-2 binding partners. GST pull-down and immunoprecipitation confirmed the individual interactions between nesprin-2/telethonin and nesprin-2/FHL-2, and showed that nesprin-2 and telethonin binding was dependent on telethonin phosphorylation status. Importantly, the interactions between these binding partners were impaired by mutations in nesprin-2, telethonin, and FHL-2 identified in EDMD with DCM and hypertrophic cardiomyopathy patients. These data suggest that nesprin-2 is a novel sarcomeric scaffold protein that may potentially participate in the maintenance and/or regulation of sarcomeric organization and function. |
