The Journal of Membrane Biology

, Volume 131, Issue 2, pp 93–104

Membrane-delimited cell signaling complexes: Direct ion channel regulation by G Proteins

  • Arthur M. Brown
Topical Review

DOI: 10.1007/BF02791318

Cite this article as:
Brown, A.M. J. Membrain Biol. (1993) 131: 93. doi:10.1007/BF02791318

Summary

Ion channels are signaling molecules and by them-selves perform no work. In this regard they are un like the usual membrane enzyme effectors for G proteins. The pathways of G protein receptor, G protein and ion channels are, therefore, purely infor mational in function. Because a single G protein may have several ion channels as effectors, the effects should be coordinated and this seems to be the case. Inhibition of Ca2+ current and stimulation of K+ currents would have a greater impact than either alone. Additional flexibility is provided by spontane ous noise in the complexes of G protein receptor, G protein, and ion channel. By having a non-zero setpoint, the range of control is extended and the responses become bi-directional.

Key Words

ion channels G proteins direct regulation membrane-delimited pathways second messengers cyto-plasmic pathways 

Abbreviations used are

ATPγS

adenosine 5’-0-(3-thiotriphosphate)

ARF

ADP-ribosylation factor

CTX

cholera toxin

DHP

dihydropyridine

G protein

guanine nucleotide-binding regulatory protein of hormone-receptor-effector functions

Gs

G protein stimulatory to adenylyl cyclase

Gk

G protein stimulatory to receptor regulated K+ channels

GDP/gbS

guanosine 5’-0-(2-thiodiphosphate)

GMP-P(NH)P

guanyl-5’-yl imidodiphosphate

GTPβS

guanosine 5’-0-(3-thiothriphosphate)

protein kinase A

cAMP-dependent protein kinase

PTX

pertussis toxin (also called IAP or islet activating protein)

T-tubule membranes

mem brane vesicles of the skeletal muscle traverse tubular system

Cyclic AMP

adenosine 3’,5’-cyclic monophosphate

Cyclic GMP

guanosine 3’,5’-cyclic monophosphate

NAD+

nicotinamide adenine dinucleotide

Copyright information

© Springer-Verlag New York Inc. 1993

Authors and Affiliations

  • Arthur M. Brown
    • 1
  1. 1.Department of Molecular Physiology and BiophysicsBaylor College of MedicineHouston

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