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

© 2024 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society..

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.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:240

Enthalten in:

Acta physiologica (Oxford, England) - 240(2024), 4 vom: 17. Apr., Seite e14125

Sprache:

Englisch

Beteiligte Personen:

Luo, Min [VerfasserIn]
Liu, Yongjian [VerfasserIn]
Nikolovska, Katerina [VerfasserIn]
Riederer, Brigitte [VerfasserIn]
Patrucco, Enrico [VerfasserIn]
Hofmann, Franz [VerfasserIn]
Seidler, Ursula [VerfasserIn]

Links:

Volltext

Themen:

Brush border membrane
Cyclic GMP-Dependent Protein Kinases
EC 2.7.11.12
Heat‐stable Escherichia coli enterotoxin
Journal Article
PDZ‐adaptor proteins
Slc9a3
Sodium‐hydrogen exchanger
Sodium-Hydrogen Exchanger 3
Sodium-Hydrogen Exchangers
Traveler's diarrhea

Anmerkungen:

Date Completed 17.04.2024

Date Revised 17.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/apha.14125

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370235312