Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. STKE, 26 November 2002
Vol. 2002, Issue 160, p. tw441
[DOI: 10.1126/stke.2002.160.tw441]


Channels More Versatility of Homer

Homer proteins have been characterized as adaptor proteins in signaling complexes associated with metabotropic glutamate receptors. Homer proteins bind both the receptor and inositol 1,4,5-trisphosphate receptors in these complexes. Noting that Ryanodine receptor type 1 (RyR1) also has a putative Homer-binding sequence, Feng et al. explored the functional relation of these proteins. Endogenous Homer proteins could be immunoprecipitated with RyR1 from extracts of rat skeletal muscle. Recordings from single RyR1 channels reconstituted in bilayer lipid membranes showed that Homer proteins enhanced the open probability of the RyR1 channel. Assays with sarcoplasmic reticulum vesicles from skeletal muscle showed that Homer proteins increased efficacy of Ca2+ and caffeine in activating RyR1. Although the truncated, short form of Homer1 is thought to function in a dominant-negative manner in some systems, both the long and short forms of Homer1 had similar effects on the RyR1 channel. The authors discuss this new role of Homer in regulating the gain of excitation-contraction coupling in muscle cells. For more on Homer, see the STKE Review by Fagni et al.

W. Feng, J. Tu, T. Yang, P. S. Vernon, P. D. Allen, P. F. Worley, I. N. Pessah. Homer regulates gain of ryanodine receptor type 1 channel complex. J. Biol. Chem. 277, 44722-44730 (2002). [Abstract] [Full Text]

L. Fagni, P. F. Worley, F. Ango, Homer as both a scaffold and transduction molecule. Science's STKE (2002),;2002/137/re8 [Abstract] [Full Text]

Citation: More Versatility of Homer. Sci. STKE 2002, tw441 (2002).

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882