{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nAlthough the query asks for a summary on MIR4804, none of the provided abstracts mention or discuss MIR4804. Instead, the abstracts collectively focus on KCNE3, a single transmembrane‐spanning regulatory subunit that plays diverse roles by modulating multiple voltage‐gated K⁺ channels in different tissues. For instance, in epithelial cells, KCNE3 partners with KCNQ1 to create heteromeric channels that facilitate transepithelial Cl⁻ secretion in the intestine and trachea, an action essential for proper fluid and electrolyte balance (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nAt the biophysical level, KCNE3 influences channel gating by modifying the voltage-sensing properties of channel α-subunits. Studies have shown that when KCNE3 interacts with KCNQ1, it stabilizes the S4 segment in an active state, leading to voltage-independent channel activity, in stark contrast to the resting state stabilization produced by its homolog KCNE1 (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn cardiac and adrenal contexts, KCNE3 is implicated in complex arrhythmogenic mechanisms. Disruption of KCNE3 results not only in direct alterations of cardiac repolarization but also, as demonstrated in knockout mice, in secondary hyperaldosteronism associated with an adrenal-specific lymphocyte infiltration. These changes culminate in delayed ventricular repolarization and an increased susceptibility to arrhythmias (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "], ["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nBeyond excitable tissues, KCNE3 serves as a highly selective marker for endothelial tip cells during angiogenesis. Its early and restricted expression in sprouting vessels – and responsiveness to VEGFA – underscore a potential role in vascular patterning and neovascular therapeutic targeting (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "5"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn the auditory system, KCNE3 contributes to the regulation of spiral ganglion neuron excitability. Its deletion leads to significant alterations in resting membrane potential and action potential properties, suggesting that KCNE3 helps shape auditory neuron firing and may be involved in disorders such as Meniere disease and tinnitus (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "6"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nWithin the central nervous system, KCNE3 (often acting in tandem with KCNE1) modulates currents through channels like Kv12.2 by affecting both channel surface expression and gating properties. Silencing experiments indicate that removal of KCNE3 leads to increased channel trafficking and a shift to hyperpolarized activation, highlighting its role as an inhibitor of channel membrane expression and gating in neurons (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "7"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn atrial tissues, loss of KCNE3 predisposes to atrial fibrillation through androgen- and aldosterone-dependent mechanisms. Specifically, KCNE3 deletion enhances the recycling of Kv1.5 channels via Rab GTPase-mediated pathways, leading to shortened effective refractory periods and an increased likelihood of AF induction (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "8"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nFinally, in skeletal muscle, KCNE3 is necessary for normal muscle function and fiber composition. Analyses in knockout mice reveal that the absence of KCNE3 results in altered expression of key K⁺ channel subunits, a shift toward a more oxidative fiber profile, and impaired contractile performance, as evidenced by both in vivo and in vitro functional deficits (["}, {"type": "fg", "children": [{"type": "fg_f", "ref": "9"}]}, {"type": "t", "text": "]). \n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Patricia Preston, Lena Wartosch, Dorothee Günzel, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Disruption of the K+ channel beta-subunit KCNE3 reveals an important role in intestinal and tracheal Cl- transport."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M109.047829"}], "href": "https://doi.org/10.1074/jbc.M109.047829"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20051516"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20051516"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Koichi Nakajo, Yoshihiro Kubo "}, {"type": "b", "children": [{"type": "t", "text": "KCNE1 and KCNE3 stabilize and/or slow voltage sensing S4 segment of KCNQ1 channel."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Gen Physiol (2007)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1085/jgp.200709805"}], "href": "https://doi.org/10.1085/jgp.200709805"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "17698596"}], "href": "https://pubmed.ncbi.nlm.nih.gov/17698596"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Geoffrey W Abbott "}, {"type": "b", "children": [{"type": "t", "text": "KCNE1 and KCNE3: The yin and yang of voltage-gated K(+) channel regulation."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Gene (2016)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.gene.2015.09.059"}], "href": "https://doi.org/10.1016/j.gene.2015.09.059"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "26410412"}], "href": "https://pubmed.ncbi.nlm.nih.gov/26410412"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Zhaoyang Hu, Shawn M Crump, Marie Anand, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Kcne3 deletion initiates extracardiac arrhythmogenesis in mice."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "FASEB J (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1096/fj.13-241828"}], "href": "https://doi.org/10.1096/fj.13-241828"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24225147"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24225147"}]}, {"type": "r", "ref": 5, "children": [{"type": "t", "text": "Ron A Deckelbaum, Ivan B Lobov, Eunice Cheung, et al. "}, {"type": "b", "children": [{"type": "t", "text": "The potassium channel Kcne3 is a VEGFA-inducible gene selectively expressed by vascular endothelial tip cells."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Angiogenesis (2020)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1007/s10456-019-09696-8"}], "href": "https://doi.org/10.1007/s10456-019-09696-8"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31754927"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31754927"}]}, {"type": "r", "ref": 6, "children": [{"type": "t", "text": "Wenying Wang, Hyo Jeong Kim, Jeong-Han Lee, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Functional significance of K+ channel β-subunit KCNE3 in auditory neurons."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M113.545236"}], "href": "https://doi.org/10.1074/jbc.M113.545236"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24727472"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24727472"}]}, {"type": "r", "ref": 7, "children": [{"type": "t", "text": "Sinead M Clancy, Bihan Chen, Federica Bertaso, et al. "}, {"type": "b", "children": [{"type": "t", "text": "KCNE1 and KCNE3 beta-subunits regulate membrane surface expression of Kv12.2 K(+) channels in vitro and form a tripartite complex in vivo."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0006330"}], "href": "https://doi.org/10.1371/journal.pone.0006330"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19623261"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19623261"}]}, {"type": "r", "ref": 8, "children": [{"type": "t", "text": "Ulrike Lisewski, Clemens Koehncke, Nicola Wilck, et al. 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