{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nAlthough the provided abstracts do not directly mention SNORD115‐46, they both examine the roles of an auxiliary subunit—commonly referred to as the β2 subunit (encoded by KCNMB2)—in modulating large conductance Ca²⁺‐activated K⁺ (BK) channels. In adrenal medullary chromaffin cells, the β2 subunit normally confers a fast inactivation to the BK current and shifts the voltage‐activation range. Genetic deletion of β2 results in the complete loss of BK current inactivation, which in turn slows action potential repolarization, diminishes repetitive firing during current injection, and paradoxically increases the tendency for spontaneous burst firing. These findings indicate that the β2 subunit is critical for fine-tuning the excitability and firing patterns of these neuroendocrine cells."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn a related investigation of BK channels in colonic epithelia, the global knockout of the β2 subunit reveals that while basal and ATP-induced K⁺ conductances remain comparable to wild-type, under conditions that stimulate aldosterone-dependent K⁺ secretion the absence of the β2 subunit results in increased secretion. The study further establishes that the apical K⁺ conductance is mediated by KCa1.1 channels (sensitive to iberiotoxin) and that no compensatory transcriptional regulation by other β subunits occurs. This suggests that in colonic tissues, the β2 subunit may serve not as an essential activator but rather as a modulator that restrains KCa1.1 channel activity under specific physiological conditions."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Pedro L Martinez-Espinosa, Chengtao Yang, Vivian Gonzalez-Perez, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Knockout of the BK β2 subunit abolishes inactivation of BK currents in mouse adrenal chromaffin cells and results in slow-wave burst activity."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Gen Physiol (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1085/jgp.201411253"}], "href": "https://doi.org/10.1085/jgp.201411253"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25267913"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25267913"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Casper K Larsen, Helle A Praetorius, Jens Leipziger, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Intact colonic K"}, {"type": "a", "children": [{"type": "t", "text": "sub"}], "href": "sub"}, {"type": "t", "text": "C"}, {"type": "a", "children": [{"type": "t", "text": "/sub"}], "href": "/sub"}, {"type": "a", "children": [{"type": "t", "text": "sub"}], "href": "sub"}, {"type": "t", "text": "a"}, {"type": "a", "children": [{"type": "t", "text": "/sub"}], "href": "/sub"}, {"type": "t", "text": "1.1 channel activity in KCNMB2 knockout mice."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Physiol Rep (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.14814/phy2.13179"}], "href": "https://doi.org/10.14814/phy2.13179"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "28292889"}], "href": "https://pubmed.ncbi.nlm.nih.gov/28292889"}]}]}]}