Nesprin-1-alpha2 associates with kinesin at myotube outer nuclear membranes, but is restricted to neuromuscular junction nuclei in adult muscle
Abstract
Nesprins, nuclear envelope spectrin-repeat proteins encoded by the SYNE1 and SYNE2 genes, are involved in localization of nuclei. The short isoform, nesprin-1-alpha2, is required for relocation of the microtubule organizer function from centromeres to the nuclear rim during myogenesis. Using specific antibodies, we now show that both nesprin-1-alpha2 and nesprin-1-giant co-localize with kinesin at the junctions of concatenated nuclei and at the outer poles of nuclear chains in human skeletal myotubes. In adult muscle, nesprin-1-alpha2 was found, together with kinesin, only on nuclei associated with neuromuscular junctions, whereas all adult cardiomyocyte nuclei expressed nesprin-1-alpha2. In a proteomics study, kinesin heavy and light chains were the only significant proteins in myotube extracts pulled down by nesprin-1-alpha2, but not by a mutant lacking the highly-conserved STAR domain (18 amino-acids, including the LEWD motif). The results support a function for nesprin-1-alpha2 in the specific localization of skeletal muscle nuclei mediated by kinesins and suggest that its primary role is at the outer nuclear membrane.
Citation
Holt , I , Fuller , H R , Lam , L T , Sewry , C A , Shirran , S L , Zhang , Q , Shanahan , C M & Morris , G E 2019 , ' Nesprin-1-alpha2 associates with kinesin at myotube outer nuclear membranes, but is restricted to neuromuscular junction nuclei in adult muscle ' , Scientific Reports , vol. 9 , 14202 . https://doi.org/10.1038/s41598-019-50728-6
Publication
Scientific Reports
Status
Peer reviewed
ISSN
2045-2322Type
Journal article
Description
This project was supported by grants from the British Heart Foundation (PG/11/71/29091 and PG/16/68/31991) and the Orthopaedic Institute Ltd., (RJAH Orthopaedic Hospital, Oswestry, UK).Collections
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