The action of cytoplasmic calcium on the cGMP-activated channel in salamander rod photoreceptors

The Journal of Physiology
M S Sagoo, L Lagnado

Abstract

1. Truncated salamander rod photoreceptors were internally perfused to investigate the action of cytoplasmic Ca2+ on cGMP-activated channels in the outer segment. 2. Switching from 1 microM Ca2+ to 0 Ca2+ increased the cGMP-activated current by a factor of 7.1 +/- 0.5 when measured in the first 60 s after the outer segment was opened to the bath, but only 2-fold after 5 min or more. This was attributed to the loss from the outer segment of a soluble factor required for Ca2+ to inhibit the cGMP-activated channel. 3. Short exposures to 0 Ca2+ caused an irreversible increase in the cGMP-activated current measured in 1 microM Ca2+, indicating that lowering [Ca2+] accelerated the loss of the channel inhibitor from the outer segment. 4. Channel activation occurred with a half-time of 6.7 s on switching to 0 Ca2+. Replacing 1 microM Ca2+ inhibited the current again with a half-time of 11.0 s. 5. The inhibition of the cGMP-activated current by Ca2+ could be described by a Hill curve with half-maximal suppression at 55 +/- 13 nM Ca2+ and a Hill coefficient of 1.4 +/- 0.4. 6. Addition of calmodulin (1 microM), or the calmodulin inhibitors mastoparan and calmidazolium (5 microM), did not alter the action of Ca2+ on the cGMP-activated curr...Continue Reading

Citations

Mar 27, 2013·The Journal of General Physiology·Gucan DaiMichael D Varnum
Nov 14, 1997·The Journal of General Physiology·D H Hackos, J I Korenbrot
Jun 27, 2009·Proceedings of the National Academy of Sciences of the United States of America·Norihiko TakemotoSatoru Kawamura
Aug 25, 2001·Annual Review of Neuroscience·M E Burns, D A Baylor
Aug 18, 2004·The Journal of General Physiology·Matthew C Trudeau, William N Zagotta
Mar 21, 2006·BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology·Gordon L Fain
Jun 28, 2002·Physiological Reviews·U Benjamin Kaupp, Reinhard Seifert
Jan 30, 2002·The Journal of General Physiology·Peter D CalvertClint L Makino
Nov 11, 1999·Proceedings of the National Academy of Sciences of the United States of America·M E GrunwaldK W Yau
Jan 12, 2001·Physiological Reviews·G L FainY Koutalos
Apr 28, 2021·Scientific Reports·Teemu Turunen, Ari Koskelainen

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.