{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nMembers of the Clk kinase family have emerged as critical regulators of pre‐mRNA splicing and cellular response to external cues. In multiple systems, Clk1/4 activity modulates the timing and efficiency of splicing events—for example, by suspending or promoting the maturation of specific transcripts under stress conditions or in response to insulin signaling. In this context, phosphorylation of serine/arginine‐rich splicing factors orchestrates alternative splicing programs that govern not only the expression of key regulatory proteins during stress adaptation and adipogenesis but also the processing of viral mRNAs during influenza infection."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "4"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn parallel, a related isoform—the evolutionarily conserved clk-1 (or MCLK1 in mammals)—functions as a mitochondrial hydroxylase that is essential for ubiquinone (coenzyme Q) biosynthesis. This enzyme belongs to the carboxylate-bridged diiron protein family and uniquely employs NADH directly to activate dioxygen for substrate oxidation. Experimental models ranging from in vitro enzymology to transgenic mouse studies indicate that modulating clk-1 expression significantly impacts mitochondrial respiration, cellular ATP levels, and metabolic efficiency. Moreover, altered clk-1 activity influences neuroinflammatory signaling and can extend lifespan by modifying energy metabolism in metabolically active tissues."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "5", "end_ref": "8"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nCollectively, these studies illustrate the dual functionality of ETDB-associated proteins in coordinating gene expression and mitochondrial homeostasis. By tightly regulating alternative splicing and maintaining coenzyme Q-dependent bioenergetics, these enzymes enable cells to integrate extracellular signals (such as stress and insulin) with metabolic and inflammatory responses, thereby influencing processes as diverse as cellular differentiation, antiviral defense, neuroinflammation, and even organismal lifespan."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "8"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Kun Jiang, Niketa A Patel, James E Watson, et al. 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"}, {"type": "b", "children": [{"type": "t", "text": "Clk/STY (cdc2-like kinase 1) and Akt regulate alternative splicing and adipogenesis in 3T3-L1 pre-adipocytes."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2013)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0053268"}], "href": "https://doi.org/10.1371/journal.pone.0053268"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "23308182"}], "href": "https://pubmed.ncbi.nlm.nih.gov/23308182"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Anita Artarini, Michael Meyer, Yu Jin Shin, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Regulation of influenza A virus mRNA splicing by CLK1."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Antiviral Res (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.antiviral.2019.06.003"}], "href": "https://doi.org/10.1016/j.antiviral.2019.06.003"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31176694"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31176694"}]}, {"type": "r", "ref": 5, "children": [{"type": "t", "text": "Rachel K Behan, Stephen J Lippard "}, {"type": "b", "children": [{"type": "t", "text": "The aging-associated enzyme CLK-1 is a member of the carboxylate-bridged diiron family of proteins."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Biochemistry (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1021/bi101475z"}], "href": "https://doi.org/10.1021/bi101475z"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20923139"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20923139"}]}, {"type": "r", "ref": 6, "children": [{"type": "t", "text": "Mayumi Takahashi, Takahiko Shimizu, Takuji Shirasawa "}, {"type": "b", "children": [{"type": "t", "text": "Reversal of slow growth and heartbeat through the restoration of mitochondrial function in clk-1-deficient mouse embryos by exogenous administration of coenzyme Q10."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Exp Gerontol (2012)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.exger.2012.03.008"}], "href": "https://doi.org/10.1016/j.exger.2012.03.008"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "22465812"}], "href": "https://pubmed.ncbi.nlm.nih.gov/22465812"}]}, {"type": "r", "ref": 7, "children": [{"type": "t", "text": "Kazuhide Takahashi, Yoshihiro Noda, Ikuroh Ohsawa, et al. 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