Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

C-terminal region of the UV-B photoreceptor UVR8 initiates signaling through interaction with the COP1 protein

Catherine Cloix, Eirini Kaiserli, Monika Heilmann, Katherine J. Baxter, Bobby A. Brown, Andrew O'Hara, Brian O. Smith, John M. Christie and Gareth I. Jenkins
Proceedings of the National Academy of Sciences of the United States of America
Vol. 109, No. 40 (October 2, 2012), pp. 16366-16370
Stable URL: http://www.jstor.org/stable/41763254
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
C-terminal region of the UV-B photoreceptor UVR8 initiates signaling through interaction with the COP1 protein
Preview not available

Abstract

UV-B light initiates photomorphogenic responses in plants. Arabidopsis UV RESISTANCE LOCUS8 (UVR8) specifically mediates these responses by functioning as a UV-B photoreceptor. UV-B exposure converts UVR8 from a dimer to a monomer, stimulates the rapid accumulation of UVR8 in the nucleus, where it binds to chromatin, and induces interaction of UVR8 with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1), which functions with UVR8 to control photomorphogenic UV-B responses. Although the crystal structure of UVR8 reveals the basis of photoreception, it does not show how UVR8 initiates signaling through interaction with COP1. Here we report that a region of 27 amino acids from the C terminus of UVR8 (C27) mediates the interaction with COP1. The C27 region is necessary for UVR8 function in the regulation of gene expression and hypocotyl growth suppression in Arabidopsis. However, UVR8 lacking C27 still undergoes UV-B–induced monomerization in both yeast and plant protein extracts, accumulates in the nucleus in response to UV-B, and interacts with chromatin at the UVR8-regulated ELONGATED HYPOCOTYLS (HY5) gene. The UV-B–dependent interaction of UVR8 and COP1 is reproduced in yeast cells and we show that C27 is both necessary and sufficient for the interaction of UVR8 with the WD40 domain of COP1. Furthermore, we show that C27 interacts in yeast with the REPRESSOR OF UV-B PHOTOMORPHOGENESIS proteins, RUP1 and RUP2, which are negative regulators of UVR8 function. Hence the C27 region has a key role in UVR8 function.

Page Thumbnails

  • Thumbnail: Page 
[16366]
    [16366]
  • Thumbnail: Page 
16367
    16367
  • Thumbnail: Page 
16368
    16368
  • Thumbnail: Page 
16369
    16369
  • Thumbnail: Page 
16370
    16370