{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nPPP3R2 encodes one isoform of the regulatory subunits for calcineurin—a Ca²⁺/calmodulin‐dependent serine/threonine phosphatase involved in diverse calcium‐mediated signal transduction pathways. Unlike its ubiquitously expressed counterpart PPP3R1, PPP3R2 is predominantly expressed in the testis. Studies in rat and mouse first identified this isoform, and subsequent work confirmed that the human homologue (designated PPP3RL) exhibits high sequence conservation and similarly restricted expression, likely due to tissue‐specific promoter demethylation. This specificity supports a role for PPP3R2 in modulating calcineurin activity in a context‐dependent manner, particularly in reproductive tissues."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}, {"type": "p", "children": [{"type": "t", "text": "\nBeyond its biochemical role, genetic association studies have implicated the chromosomal region downstream of PPP3R2 in complex diseases and physiological adaptations. A genome‐wide scan in inflammatory bowel disease (IBD) identified a replicated association between a PPP3R2‐corresponding locus and both Crohn’s disease and ulcerative colitis, suggesting that genetic variation at this locus may contribute to disease susceptibility. Moreover, investigations in young adults undergoing endurance training have revealed that specific PPP3R2 polymorphisms are associated with favorable adaptations in cardiac parameters—such as improved ejection fraction after exercise—and running economy. This positions PPP3R2 as a candidate gene influencing both inflammatory pathways and cardiac as well as skeletal muscle performance in response to physical stress."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "2", "end_ref": "4"}]}, {"type": "t", "text": ""}, {"type": "p", "children": [{"type": "t", "text": "\nCollectively, the available evidence highlights a dual role for PPP3R2: it contributes to the regulation of calcineurin phosphatase activity through its tissue‐specific expression and, additionally, genetic variation within or near the gene appears to modulate complex traits related to inflammatory bowel disease and endurance-related cardiac function. Future studies aimed at elucidating the mechanistic links between PPP3R2 expression, calcineurin signaling, and these phenotypic outcomes will be critical to understanding its broader biological impact."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "4"}]}]}]}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Lingling Liu, Jianxuan Zhang, Jian Yuan, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Characterization of a human regulatory subunit of protein phosphatase 3 gene (PPP3RL) expressed specifically in testis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Biol Rep (2005)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1007/s11033-004-4250-4"}], "href": "https://doi.org/10.1007/s11033-004-4250-4"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "15865209"}], "href": "https://pubmed.ncbi.nlm.nih.gov/15865209"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Andre Franke, Jochen Hampe, Philip Rosenstiel, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Systematic association mapping identifies NELL1 as a novel IBD disease gene."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2007)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0000691"}], "href": "https://doi.org/10.1371/journal.pone.0000691"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "17684544"}], "href": "https://pubmed.ncbi.nlm.nih.gov/17684544"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Zi-Hong He, Yang Hu, Hai-Yan Wang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Are calcineurin genes associated with endurance phenotype traits?"}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Eur J Appl Physiol (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1007/s00421-010-1361-6"}], "href": "https://doi.org/10.1007/s00421-010-1361-6"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20107831"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20107831"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Zi-Hong He, Yang Hu, Yan-Chun Li, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Polymorphisms in the calcineurin genes are associated with the training responsiveness of cardiac phenotypes in Chinese young adults."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Eur J Appl Physiol (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1007/s00421-010-1558-8"}], "href": "https://doi.org/10.1007/s00421-010-1558-8"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20593291"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20593291"}]}]}]}