Agrin is a component of the extracellular matrix that regulates aspects of neuromuscular junction differentiation. Identification of agrin-binding proteins has lead to the suggestion that alpha-dystroglycan is a muscle cell surface proteoglycan that mediates agrin activity. To further test this hypothesis, we have compared the ability of differentially active agrin isoforms to interact with a model component of proteoglycans, heparin, as well as with the putative proteoglycan alpha-dystroglycan. We demonstrate that an alternately spliced exon (encoding the sequence lysine, serine, arginine, lysine: Y site) is necessary for agrin-heparin interactions. We also show that alternate splicing at another site (Z site) dramatically affects interaction of alpha-dystroglycan with agrin. We propose a model in which multiple distinct domains of agrin interact with both protein and sugar moieties of alpha-dystroglycan. The isoform-specific binding of agrin to alpha-dystroglycan is consistent with a functional role for this interaction during synaptogenesis.
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http://dx.doi.org/10.1242/dev.122.5.1663 | DOI Listing |
BMC Biol
November 2024
Tissue Engineering Group, Department of Histology, University of Granada, Avenida Doctor Jesús Candel Fábregas, 11, E18016, Granada, Spain.
Adv Healthc Mater
January 2025
Translational Tissue Engineering Center, School of Medicine, Johns Hopkins University, Baltimore, MD, 21231, USA.
Neuromuscular deficits compound the loss of contractile tissue in volumetric muscle loss (VML). Two avenues for promoting recovery are neuromuscular junction (NMJ)-promoting substrates (e.g.
View Article and Find Full Text PDFCell Death Differ
November 2024
Department of Biology, Faculty of Science, Hong Kong Baptist University, Hong Kong, China.
Growing evidence indicates that brain-derived neurotrophic factor (BDNF) is produced in contracting skeletal muscles and is secreted as a myokine that plays an important role in muscle metabolism. However, the involvement of muscle-generated BDNF and the regulation of its vesicular trafficking, localization, proteolytic processing, and spatially restricted release during the development of vertebrate neuromuscular junctions (NMJs) remain largely unknown. In this study, we first reported that BDNF is spatially associated with the actin-rich core domain of podosome-like structures (PLSs) at topologically complex acetylcholine receptor (AChR) clusters in cultured Xenopus muscle cells.
View Article and Find Full Text PDFExp Physiol
January 2025
Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan.
Eur J Med Res
October 2024
Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), No.54 Youdian Road, Hangzhou, 310006, Zhejiang Province, China.
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