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A photoreceptor going nowhere but the nucleus
1Department of Molecular, Cell & Developmental Biology; University of California; Los Angeles, California USA.
Plant Signaling & Behavior
|October 21, 2009
Summary
Newly synthesized cryptochrome 2 (CRY2) photoreceptor is inactive in the cytosol. It is imported into the nucleus for phosphorylation, function, ubiquitination, and degradation, completing its life cycle in one compartment.
Area of Science:
- Plant molecular biology
- Photoreceptor signaling
Background:
- Cryptochrome 2 (CRY2) is a blue/UV-A light receptor in Arabidopsis.
- CRY2 regulates cell elongation and floral initiation.
- CRY2 is a nuclear protein involved in gene expression and plant development.
Purpose of the Study:
- To investigate the subcellular localization and post-translational events of CRY2.
- To understand the cellular events from synthesis to degradation of CRY2.
Main Methods:
- Cellular localization studies.
- Analysis of protein modification and degradation pathways.
Main Results:
- Freshly synthesized CRY2 is inactive in the cytosol.
- CRY2 is imported into the nucleus where it is phosphorylated, functional, ubiquitinated, and degraded.
- This represents the first described instance of a photoreceptor completing its entire post-translational life cycle within a single subcellular compartment.
Conclusions:
- The nucleus is the sole compartment for CRY2's post-translational modifications and functional cycle.
- This compartmentalization ensures proper regulation of CRY2's light-sensing and signaling functions.
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