{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nRecent discoveries have revealed a conserved micropeptide, SPAAR (small regulatory polypeptide of amino acid response), encoded within long noncoding RNA LINC00961. SPAAR localizes to late endosomal/lysosomal compartments where it binds to the lysosomal v‐ATPase complex to negatively regulate mTORC1 activation in response to amino acid stimulation. This modulation is critical during muscle regeneration; upon acute injury, the downregulation of SPAAR facilitates efficient mTORC1 activation and thereby promotes tissue repair and regeneration."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn addition, emerging studies indicate that the LINC00961 transcript and its encoded SPAAR extend their regulatory influence to endothelial cell function, suggesting that SPAAR may broadly modulate key signaling pathways integral not only to metabolic control and muscle homeostasis but also to vascular biology."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Akinobu Matsumoto, Alessandra Pasut, Masaki Matsumoto, et al. "}, {"type": "b", "children": [{"type": "t", "text": "mTORC1 and muscle regeneration are regulated by the LINC00961-encoded SPAR polypeptide."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Nature (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/nature21034"}], "href": "https://doi.org/10.1038/nature21034"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "28024296"}], "href": "https://pubmed.ncbi.nlm.nih.gov/28024296"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Helen L Spencer, Rachel Sanders, Mounia Boulberdaa, et al. "}, {"type": "b", "children": [{"type": "t", "text": "The LINC00961 transcript and its encoded micropeptide, small regulatory polypeptide of amino acid response, regulate endothelial cell function."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cardiovasc Res (2020)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1093/cvr/cvaa008"}], "href": "https://doi.org/10.1093/cvr/cvaa008"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31990292"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31990292"}]}]}]}