Related Experiment Video

Updated: Oct 22, 2026

Inducing Daytime Circadian Phase Shifts Using Chemogenetic and Spectral Approaches
07:29

Inducing Daytime Circadian Phase Shifts Using Chemogenetic and Spectral Approaches

Published on: June 12, 2026

Involvement of cGMP in cellular melatonin responses

M Bubis1, N Zisapel

  • 1Department of Neurobiochemistry, George S Wise Faculty of Life Sciences, Tel Aviv University, Israel.

Biology of the Cell
|May 13, 1999
PubMed

Insights

Melatonin influences protein secretion in melanoma cells by modulating cyclic guanosine monophosphate (cGMP) levels. This study reveals cGMP inhibition as a key signaling pathway for melatonin in these cells.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Endocrinology

Background:

  • Melatonin affects protein secretion in murine melanoma cells via a cholera toxin-sensitive pathway.
  • Melatonin is known to modulate cyclic guanosine monophosphate (cGMP) levels in various tissues.

Purpose of the Study:

  • To investigate the role of cGMP in melatonin's effects on melanoma cells.
  • To examine how melatonin impacts cGMP levels, cGMP-phosphodiesterase activity, and protein secretion.

Main Methods:

  • Studied the effects of melatonin on melanoma cell cGMP levels and cGMP-phosphodiesterase activity.
  • Investigated the impact of cGMP analogs on melatonin-mediated protein secretion.
  • Assessed the role of cGMP-dependent protein kinases in melatonin responses.

Main Results:

  • Melatonin significantly reduced cGMP levels in melanoma cells, an effect similar to cholera toxin (CTX).
  • Activation of cGMP-dependent protein kinases abolished melatonin's effects on protein secretion.
  • Melatonin inhibited cGMP-phosphodiesterase activity in these cells.

Conclusions:

  • Melatonin's modulation of protein secretion in melanoma cells involves the inhibition of cGMP.
  • A CTX-sensitive G protein pathway mediating cGMP inhibition is likely involved in melatonin signaling.
  • These findings highlight a novel signal transduction mechanism for melatonin in melanoma cells.

More Related Videos

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development09:32

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development

Published on: June 15, 2017

Related Concept Videos

Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
The Pineal Gland01:02

The Pineal Gland

The pineal gland, a diminutive endocrine structure named for its pinecone-shaped appearance, is situated atop the third ventricle within the diencephalon region of the forebrain. This gland, composed of secretory cells known as pinealocytes arranged in compact cords and clusters around dense particles of calcium salts, plays a pivotal role in hormonal regulation.
The primary secretion of the pineal gland is the hormone melatonin, derived from serotonin. The concentration of melatonin in the...
Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Management of Insomnia01:19

Management of Insomnia

The sleep cycle, an integral part of human health, consists of several stages with distinct characteristics and functions. It begins with a transition from wakefulness to sleep, known as the light sleep phase, followed by the restorative deep sleep phase, essential for physical recovery and growth. The cycle concludes with the Rapid Eye Movement (REM) phase, characterized by high brain activity and vivid dreaming. Insomnia, a prevalent sleep disorder, involves difficulty falling asleep, staying...
Activation and Inactivation of G Proteins01:22

Activation and Inactivation of G Proteins

Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...
G-Protein Gated Ion Channels01:21

G-Protein Gated Ion Channels

GPCRs are primarily responsible for our sense of smell, taste, and vision.  The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...