Phototropins are photoreceptor proteins (specifically, flavoproteins) that mediate phototropism responses in higher plants. Along with cryptochromes and phytochromes they allow plants to respond and alter their growth in response to the light environment. Phototropins may also be important for the opening of stomata.
Phototropins are autophosphorylating protein kinases that activate in response to blue light. When blue light hits the phototropin protein in the cell membrane, the phototropin protein will unfold and undergo phosphorylation that can cause a cascade of events inside of the cell.
Phototropins are part of the phototropic sensory system in plants that causes various environmental responses in plants. Phototropins specifically will cause stems to bend towards light, and stomata to open. Also, phototropins are important in chloroplast movements inside the cell. They also mediate the first changes in stem elongation in blue light (before cryptochromes become active) and phototropin 1 also is required for blue light mediated transcript destabilization of specific mRNAs in the cell.
- Briggs WR, Olney MA (January 2001). "Photoreceptors in plant photomorphogenesis to date. Five phytochromes, two cryptochromes, one phototropin, and one superchrome". Plant Physiol. 125 (1): 85–8. PMC 1539332. PMID 11154303.
- Wada M, Kagawa T, Sato Y (2003). "Chloroplast movement". Annu Rev Plant Biol 54: 455–68. doi:10.1146/annurev.arplant.54.031902.135023. PMID 14502999.
- DeBlasio SL, Luesse DL, Hangarter RP (September 2005). "A plant-specific protein essential for blue-light-induced chloroplast movements". Plant Physiol. 139 (1): 101–14. doi:10.1104/pp.105.061887. PMC 1203361. PMID 16113226.
- Peter E, Dick B, Baeurle SA (2010). "Mechanism of signal transduction of the LOV2-Jα photosensor from Avena sativa". Nat Commun 1: 122. doi:10.1038/ncomms1121. PMID 21081920.
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