{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n Calcium‐binding protein 1 (CaBP1) is a neuron‐specific member of the calmodulin superfamily that plays a pivotal role in fine‐tuning intracellular Ca²⁺ signaling. Multiple studies have reported that CaBP1 exists in several isoforms, such as caldendrin and other splice variants, which are differentially localized in neurons and sensory cells, thereby contributing to specialized calcium signaling in the brain, retina, and cochlea."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": " \n Structurally, CaBP1 is composed of distinct domains; its C-terminal lobe acts as a high-affinity anchor that binds to target proteins, while the N-terminal lobe and intervening linker contain key elements responsible for modulating channel activity."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": " \n In the context of intracellular calcium release, CaBP1 interacts with the inositol 1,4,5-trisphosphate receptor (InsP₃R) via its C-domain, where it modifies channel gating by stabilizing intersubunit contacts and slowing the rate of channel opening."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "5", "end_ref": "7"}]}, {"type": "t", "text": " \n Moreover, CaBP1 can modulate voltage-gated calcium channels; by competing with calmodulin for overlapping binding sites on CaV1.2 channels, it inhibits Ca²⁺-dependent inactivation and promotes calcium-dependent facilitation, while similar mechanisms contribute to the regulation of CaV2.1 channels that underlie short-term synaptic plasticity."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}, {"type": "fg_f", "ref": "8"}]}, {"type": "t", "text": " \n Notably, elevated expression levels of CABP1 have been associated with poorer relapse-free survival in glioma patients, suggesting that CaBP1 may also have a role in tumor progression and could serve as a potential prognostic biomarker."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "9"}]}, {"type": "t", "text": "\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Lee P Haynes, Alexei V Tepikin, Robert D Burgoyne "}, {"type": "b", "children": [{"type": "t", "text": "Calcium-binding protein 1 is an inhibitor of agonist-evoked, inositol 1,4,5-trisphosphate-mediated calcium signaling."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2004)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M309617200"}], "href": "https://doi.org/10.1074/jbc.M309617200"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "14570872"}], "href": "https://pubmed.ncbi.nlm.nih.gov/14570872"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Tian Yang, Elizabeth S Scholl, Ning Pan, et al. 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