"cGMP-dependent kinase 2, Na<SUP>+</SUP>/H<SUP>+</SUP> exchanger NHE3, and PDZ-adaptor NHERF2 co-assemble in apical membrane microdomains"

作者全名："Luo, Min; Liu, Yongjian; Nikolovska, Katerina; Riederer, Brigitte; Patrucco, Enrico; Hofmann, Franz; Seidler, Ursula"

作者地址："[Luo, Min; Liu, Yongjian; Nikolovska, Katerina; Riederer, Brigitte; Seidler, Ursula] Hannover Med Sch, Dept Gastroenterol Hepatol Infectiol & Endocrinol, Hannover, Germany; [Luo, Min] Chongqing Med Univ, Dept Infect Dis, Affiliated Hosp 2, Chongqing, Peoples R China; [Liu, Yongjian] Chongqing Med Univ, Affiliated Hosp 2, Dept Endocrinol, Chongqing, Peoples R China; [Patrucco, Enrico; Hofmann, Franz] Tech Univ Munich, Inst Pharmakol & Toxikol, Munich, Germany; [Patrucco, Enrico] Univ Torino, Dept Mol Biotechnol & Hlth Sci, Turin, Italy; [Seidler, Ursula] Hannover Med Sch, Dept Gastroenterol Hepatol & Endocrinol, Carl Neuberg Str 1, D-30625 Hannover, Germany"

通信作者："Seidler, U (通讯作者)，Hannover Med Sch, Dept Gastroenterol Hepatol & Endocrinol, Carl Neuberg Str 1, D-30625 Hannover, Germany."

来源：ACTA PHYSIOLOGICA

ESI学科分类：BIOLOGY & BIOCHEMISTRY

WOS号：WOS:001191268200001

JCR分区：Q1

影响因子：5.6

年份：2024

卷号：　

期号：　

开始页：　

结束页：　

文献类型：Article; Early Access

关键词：brush border membrane; heat-stable Escherichia coli enterotoxin; PDZ-adaptor proteins; Slc9a3; sodium-hydrogen exchanger; traveler's diarrhea

摘要："Aim: Trafficking, membrane retention, and signal-specific regulation of the Na+/H+ exchanger 3 (NHE3) are modulated by the Na+/H+ Exchanger Regulatory Factor (NHERF) family of PDZ-adapter proteins. This study explored the assembly of NHE3 and NHERF2 with the cGMP-dependent kinase II (cGKII) within detergent-resistant membrane microdomains (DRMs, ""lipid rafts"") during in vivo guanylate cycle C receptor (Gucy2c) activation in murine small intestine. Methods: Small intestinal brush border membranes (siBBMs) were isolated from wild type, NHE3-deficient, cGMP-kinase II-deficient, and NHERF2-deficient mice, after oral application of the heat-stable Escherichia coli toxin (STa) analog linaclotide. Lipid raft and non-raft fractions were separated by Optiprep density gradient centrifugation of Triton X-solubilized siBBMs. Confocal microscopy was performed to study NHE3 redistribution after linaclotide application in vivo. Results: In the WT siBBM, NHE3, NHERF2, and cGKII were strongly raft associated. The raft association of NHE3, but not of cGKII, was NHERF2 dependent. After linaclotide application to WT mice, lipid raft association of NHE3 decreased, that of cGKII increased, while that of NHERF2 did not change. NHE3 expression in the BBM shifted from a microvillar to a terminal web region. The linaclotide-induced decrease in NHE3 raft association and in microvillar abundance was abolished in cGKII-deficient mice, and strongly reduced in NHERF2-deficient mice. Conclusion: NHE3, cGKII, and NHERF2 form a lipid raft-associated signal complex in the siBBM, which mediates the inhibition of salt and water absorption by Gucy2c activation. NHERF2 enhances the raft association of NHE3, which is essential for its close interaction with the exclusively raft-associated activated cGKII."

基金机构：DFG Sachbeihilfe; Volkswagen Stiftung [Z1953]; TUM pharmacological institute [33.19-42502-04-14/1605]; [SE460/21-1]; [SE 460/22-1]

基金资助正文："This project was funded by the DFG Sachbeihilfe SE460/21-1 and SE 460/22-1, and by the Volkswagen Stiftung grant Z1953. We are grateful to the animal caretakers of the MHH institute for animal research and the TUM pharmacological institute for mouse breeding. Animal experiments were performed following approved protocols of the Hannover Medical School and the local authorities for the regulation of animal welfare. The animal experimentation permission had the number 33.19-42502-04-14/1605. We are grateful to the group of Hugo deJonge for sharing the anti-cGKII antibody, and to the group of Chris Yun for sharing the anti-NHERF2 antibody. Open Access funding enabled and organized by Projekt DEAL."