Faculty Collaboration Database

Temporal coupling of cyclic AMP and Ca/calmodulin-stimulated adenylyl cyclase to the circadian clock in chick retinal photoreceptor cells. J Neurochem 2006 Nov;99(4):1142-50

Date

09/20/2006

Pubmed ID

16981891

Pubmed Central ID

PMC2729135

DOI

10.1111/j.1471-4159.2006.04154.x

Scopus ID

2-s2.0-33750440555 (requires institutional sign-in at Scopus site)   27 Citations

Abstract

cAMP signaling pathways play crucial roles in photoreceptor cells and other retinal cell types. Previous studies demonstrated a circadian rhythm of cAMP level in chick photoreceptor cell cultures that drives the rhythm of activity of the melatonin synthesizing enzyme arylalkylamine N-acetyltransferase and the rhythm of affinity of the cyclic nucleotide-gated channel for cGMP. Here, we report that the photoreceptor circadian clock generates a rhythm in Ca(2+)/calmodulin-stimulated adenylyl cyclase activity, which accounts for the temporal changes in the cAMP levels in the photoreceptors. The circadian rhythm of cAMP in photoreceptor cell cultures is abolished by treatment with the l-type Ca(2+) channel antagonist nitrendipine, while the Ca(2+) channel agonist, Bay K 8644, increased cAMP levels with continued circadian rhythmicity in constant darkness. These results indicate that the circadian rhythm of cAMP is dependent, in part, on Ca(2+) influx. Photoreceptor cell cultures exhibit a circadian rhythm in Ca(2+)/calmodulin-stimulated adenylyl cyclase enzyme activity with high levels at night and low levels during the day, correlating with the temporal changes of cAMP in these cells. Transcripts encoding two of the Ca(2+)/calmodulin-stimulated adenylyl cyclases, type 1 and type 8 (Adcy1 and Adcy8), displayed significant daily rhythms of mRNA expression under a light-dark cycle, but only the Adcy1 transcript rhythm persisted in constant darkness. Similar rhythms of Adcy1 mRNA level and Ca(2+)/calmodulin-stimulated adenylyl cyclase activity were observed in retinas of 2-week-old chickens. These results indicate that a circadian clock controls the expression of Adcy1 mRNA and Ca(2+)/calmodulin-stimulated adenylyl cyclase activity; and calcium influx into these cells gates the circadian rhythm of cAMP, a key component in the regulation of photoreceptor function.

Author List

Chaurasia SS, Haque R, Pozdeyev N, Jackson CR, Iuvone PM

Author

Shyam S. Chaurasia PhD Associate Professor in the Ophthalmology and Visual Sciences department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adenylyl Cyclases
Animals
Biological Clocks
Calcium
Calcium Channel Agonists
Calcium Channel Blockers
Calcium Signaling
Calmodulin
Cells, Cultured
Chick Embryo
Chickens
Circadian Rhythm
Cyclic AMP
Male
Membrane Proteins
Nerve Tissue Proteins
Photoreceptor Cells
RNA, Messenger