{'fraction_non_alphanumeric': 0.030186608122941824, 'fraction_numerical': 0.013172338090010977, 'mean_word_length': 6.038610038610039, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Role of syndecan‐4 side chains in turkey satellite cell growth and development

Syndecan‐4 is a cell membrane heparan sulfate proteoglycan that is composed of a core protein and covalently attached glycosaminoglycans (GAG) and N‐linked glycosylated (N‐glycosylated) chains. Syndecan‐4 has been shown to function independent of its GAG chains. Syndecan‐4 may derive its biological function from the N‐glycosylated chains due to the biological role of N‐glycosylated chains in protein folding and cell membrane localization. The objective of the current study was to investigate the role of syndecan‐4 N‐glycosylated chains and the interaction between GAG and N‐glycosylated chains in turkey myogenic satellite cell proliferation, differentiation, and fibroblast growth factor 2 (FGF2) responsiveness. The wild type turkey syndecan‐4 and the syndecan‐4 without GAG chains were cloned into the expression vector pCMS‐EGFP and used as templates to generate syndecan‐4 N‐glycosylated one‐chain and no‐chain mutants with or without GAG chains. The wild type syndecan‐4, all of the syndecan‐4 N‐glycosylated chain mutants were transfected into turkey myogenic satellite cells. Cell proliferation, differentiation, and responsiveness to FGF2 were measured. The overexpression of syndecan‐4 N‐glycosylated mutants with or without GAG chains did not change cell proliferation, differentiation, and responsiveness to FGF2 compared to the wild type syndecan‐4 except that the overexpression of syndecan‐4 N‐glycosylated mutants without GAG chains increased cell proliferation at 48 and 72 h post‐transfection. These data suggest that syndecan‐4 functions in an FGF2‐independent manner, and the N‐glycosylated and GAG chains are required for syndecan‐4 to regulate turkey myogenic satellite cell proliferation, but not differentiation.