Krapivinsky G B, Ackerman M J, Gordon E A, Krapivinsky L D, Clapham D E
Department of Pharmacology, Mayo Foundation, Rochester, Minnesota 55905.
Cell. 1994 Feb 11;76(3):439-48. doi: 10.1016/0092-8674(94)90109-0.
Cells maintain control of their volume by the passage of KCl and water across their membranes, but the regulatory proteins are unknown. Expression in Xenopus oocytes of a novel protein, pICln, activated a chloride conductance. We have cloned analogs of pICln from rat heart and Xenopus ovary. pICln was identified as an abundant soluble cytosolic protein (approximately 40 kd) that does not immunolocalize with the plasma membrane. pICln was found in epithelial and cardiac cells, brain, and Xenopus oocytes, forming complexes with soluble actin and other cytosolic proteins. Monoclonal antibodies recognizing pICln blocked activation of a native hypotonicity-induced chloride conductance (ICl.swell) in Xenopus oocytes, suggesting that pICln may link actin-bound cytoskeletal elements to an unidentified volume-sensitive chloride channel. The high degree of sequence conservation and widespread expression of pICln suggest that it is an important element in cellular volume regulation.
细胞通过氯化钾和水跨膜运输来维持其体积的控制，但调控蛋白尚不清楚。一种新型蛋白质pICln在非洲爪蟾卵母细胞中的表达激活了氯离子电导。我们已从大鼠心脏和非洲爪蟾卵巢中克隆出pICln的类似物。pICln被鉴定为一种丰富的可溶性胞质蛋白（约40kd），其免疫定位不在质膜上。pICln存在于上皮细胞、心肌细胞、脑和非洲爪蟾卵母细胞中，与可溶性肌动蛋白和其他胞质蛋白形成复合物。识别pICln的单克隆抗体可阻断非洲爪蟾卵母细胞中天然低渗诱导的氯离子电导（ICl.swell）的激活，这表明pICln可能将肌动蛋白结合的细胞骨架成分与一个未知的体积敏感氯离子通道联系起来。pICln的高度序列保守性和广泛表达表明它是细胞体积调节中的一个重要元件。
