serval:BIB_56A270ADA2A2
Lipid anchoring of Arabidopsis phototropin 1 to assess the functional significance of receptor internalization: should I stay or should I go?
10.1111/nph.13299
000352802800017
25643813
Preuten
T.
author
Blackwood
L.
author
Christie
J.M.
author
Fankhauser
C.
author
article
2015
New Phytologist
1469-8137
0028-646X
journal
206
3
1038-1050
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. 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. 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. 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.
Arabidopsis/chemistry
Arabidopsis/genetics
Arabidopsis Proteins/genetics
Arabidopsis Proteins/metabolism
Cell Membrane/metabolism
Lipid-Linked Proteins/physiology
Phosphoproteins/genetics
Phosphoproteins/metabolism
Phototropins/genetics
Phototropins/metabolism
Phototropism/genetics
Plants, Genetically Modified/metabolism
Plants, Genetically Modified/radiation effects
Signal Transduction
eng
60_published
true
peer-reviewed
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: ppublish
University of Lausanne
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