Regulation of nitric oxide-responsive recombinant soluble guanylyl cyclase by calcium

Scott J. Parkinson, Aleksandar Jovanovic, Sofija Jovanovic, Frank Wagner, Andre Terzic, Scott A. Waldman

Research output: Contribution to journalArticle

31 Scopus citations

Abstract

Calcium (Ca2+) and cyclic GMP (cGMP) subserve antagonistic functions that are reflected in their coordinated reciprocal regulation in physiological systems. However, molecular mechanisms by which Ca2+ regulates cGMP-dependent signaling remain incompletely defined. In this study, the inhibition of recombinant nitric oxide (NO)-stimulated soluble guanylyl cyclase (SGC) by Ca2+ was demonstrated. The α- and β-subunits of recombinant rat SGC were heterologously coexpressed in HEK 293 cells which do not express NO synthase, whose Ca2+-stimulated activity can confound the effects of that cation on SGC. Ca2+ inhibited basal and NO-stimulated SGC in a concentration- and guanine nucleotide-dependent fashion. This cation inhibited SGC in crude cell extracts and immunopurified preparations. Ca2+ lowered both the V(max) and K(m) of SGC via an uncompetitive mechanism through direct interaction with the enzyme. In intact HEK 293 cells, increases in the intracellular Ca2+ concentration induced by ionomycin, a Ca2+ ionophore, and thapsigargin, which releases intracellular stores of that cation, inhibited NO-stimulated intracellular cGMP accumulation. Similarly, carbachol-induced elevation of the intracellular Ca2+ concentration inhibited NO-stimulated intracellular cGMP accumulation in HEK 293 cells. These data demonstrate that SGC behaves as a sensitive Ca2+ detector that may play a central role in coordinating the reciprocal regulation of Ca2+- and cGMP-dependent signaling mechanisms.

Original languageEnglish (US)
Pages (from-to)6441-6448
Number of pages8
JournalBiochemistry
Volume38
Issue number20
DOIs
StatePublished - May 18 1999

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Regulation of nitric oxide-responsive recombinant soluble guanylyl cyclase by calcium'. Together they form a unique fingerprint.

  • Cite this

    Parkinson, S. J., Jovanovic, A., Jovanovic, S., Wagner, F., Terzic, A., & Waldman, S. A. (1999). Regulation of nitric oxide-responsive recombinant soluble guanylyl cyclase by calcium. Biochemistry, 38(20), 6441-6448. https://doi.org/10.1021/bi990154v