Lipid anchoring of Arabidopsis phototropin 1 to assess the functional significance of receptor internalization: should I stay or should I go?

Preuten, T., Blackwood, L., Christie, J. M. and Fankhauser, C. (2015) Lipid anchoring of Arabidopsis phototropin 1 to assess the functional significance of receptor internalization: should I stay or should I go? New Phytologist, 206(3), pp. 1038-1050. (doi: 10.1111/nph.13299) (PMID:25643813)

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Publisher's URL: http://dx.doi.org/10.1111/nph.13299

Abstract

The phototropin 1 (phot1) blue light receptor mediates a number of adaptive responses, including phototropism, that generally serve to optimize photosynthetic capacity. Phot1 is a plasma membrane-associated protein, but upon irradiation, a fraction is internalized into the cytoplasm. Although this phenomenon has been reported for more than a decade, its biological significance remains elusive. Here, we use a genetic approach to revisit the prevalent hypotheses regarding the functional importance of receptor internalization.<p></p> Transgenic plants expressing lipidated versions of phot1 that are permanently anchored to the plasma membrane were used to analyse the effect of internalization on receptor turnover, phototropism and other phot1-mediated responses.<p></p> Myristoylation and farnesylation effectively prevented phot1 internalization. Both modified photoreceptors were found to be fully functional in Arabidopsis, rescuing phototropism and all other phot1-mediated responses tested. Light-mediated phot1 turnover occurred as in the native receptor. Furthermore, our work does not provide any evidence of a role of phot1 internalization in the attenuation of receptor signalling during phototropism.<p></p> Our results demonstrate that phot1 signalling is initiated at the plasma membrane. They furthermore indicate that release of phot1 into the cytosol is not linked to receptor turnover or desensitization.<p></p>

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Fankhauser, Prof Christian and Christie, Professor John
Authors: Preuten, T., Blackwood, L., Christie, J. M., and Fankhauser, C.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
Journal Name:New Phytologist
Publisher:New Phytologist Trust
ISSN:0028-646X
ISSN (Online):1469-8137

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
581491Regulation of Auxin Fluxes Required For Phototropic GrowthJohn ChristieBiotechnology and Biological Sciences Research Council (BBSRC)BB/J016047/1RI MOLECULAR CELL & SYSTEMS BIOLOGY
500151Doctoral Training Grant 2009-15Timothy PalmerBiotechnology and Biological Sciences Research Council (BBSRC)BB/F016735/1RI CARDIOVASCULAR & MEDICAL SCIENCES
500152Doctoral Training Grant 2009-15Timothy PalmerBiotechnology and Biological Sciences Research Council (BBSRC)BB/F016735/1RI CARDIOVASCULAR & MEDICAL SCIENCES