The Journal of General Physiology
Avanti Polar Lipids
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text (PDF, 1584K)
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hamm, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hamm, H.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

The Journal of General Physiology, Vol 95, 545-567, Copyright © 1990 by The Rockefeller University Press

ARTICLES

Regulation by light of cyclic nucleotide-dependent protein kinases and their substrates in frog rod outer segments

H Hamm
Department of Physiology and Biophysics, University of Illinois College of Medicine, Chicago 60612.

Cyclic nucleotides (both cAMP and cGMP) stimulate the phosphorylation of several proteins of 65-70, 50-52, 21, 13, and 12 kD in rod outer segments (ROS) of the frog retina. Subcellular fractionation showed that phosphopeptides of 67, 21, 13, and 12 kD were soluble and phosphopeptides of 69, 67, 50-52, and 12 kD were membrane associated at physiological ionic strength. Components I and II, 13 and 12 kD, respectively, are the major cyclic nucleotide-dependent phosphoproteins of ROS and have been reported to be phosphorylated in the dark and dephosphorylated in the light. Under unstimulated conditions, phosphorylated Components I and II were found in the soluble fraction. Cyclic nucleotide stimulation of phosphorylation resulted in increased phospho-Components I and II in the soluble fraction, and phospho- Component II on the membrane. Light had no effect on the phosphorylation level of soluble Components I and II, but it caused a depletion within 1 s of the membrane-bound phospho-Component II. A half- maximal decrease in membrane-bound Component II was seen at 5 x 10(5) rhodopsins bleached per outer segment. The cyclic nucleotide-dependent protein kinase(s) were found primarily in the peripheral membrane fraction of ROS proteins. 8-bromo cyclic AMP was two orders of magnitude more effective than 8-bromo cyclic GMP at stimulating Component I and II phosphorylation. An active peptide of the Walsh inhibitor of cAMP-dependent protein kinase [PKI(5-22)amide] blocked the phosphorylation with an IC50 of 10 nM. Photoaffinity labeling studies with 8-N3-cAMP and 8-N3-cGMP revealed the presence of a 52-kD band specifically labeled with 8-N3-cAMP, but no specific 8-N3-cGMP labeling. These data suggest that cyclic nucleotide-dependent protein phosphorylation in ROS occurs via the activation of a cAMP-dependent protein kinase.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
J. F. Wilkins, M. W. Bitensky, and B. M. Willardson
Regulation of the Kinetics of Phosducin Phosphorylation in Retinal Rods
J. Biol. Chem., August 9, 1996; 271(32): 19232 - 19237.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
C. D. Thulin, J. R. Savage, J. N. McLaughlin, S. M. Truscott, W. M. Old, N. G. Ahn, K. A. Resing, H. E. Hamm, M. W. Bitensky, and B. M. Willardson
Modulation of the G Protein Regulator Phosducin by Ca2+/Calmodulin-dependent Protein Kinase II Phosphorylation and 14-3-3 Protein Binding
J. Biol. Chem., June 22, 2001; 276(26): 23805 - 23815.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents