Disease relevance of PHOT2

• Moreover, the data obtained from full-length Arabidopsis phot1 and phot2 expressed in insect cells closely resemble those obtained for the tandem LOV-domain fusion proteins expressed in E. coli [1].

High impact information on PHOT2

• Phototropin-related NPL1 controls chloroplast relocation induced by blue light [2].
• These results indicate that NPL1 may function as a photoreceptor mediating chloroplast relocation [2].
• Phot1 is plasma membrane associated and, as with phot2, has been shown to function as a photoreceptor for phototropism, blue light-induced chloroplast movement, and blue light-induced stomatal opening [3].
• Bacterially expressed Arabidopsis phototropin 2 kinase domain (KD) with GST-tag showed a constitutive kinase activity on casein, a common in vitro substrate of Ser/Thr protein kinase [4].
• In phot1 and phot1/phot2 mutants, net Ca(2+) flux remained steady [5].

Biological context of PHOT2

• In Arabidopsis thaliana, phototropism of seedling and plant stems is under the control of two paralogous genes, PHOT1 and PHOT2, that encode different phototropins with partially redundant light response qualities [6].
• In vitro experiments indicate that cross phosphorylation can occur between functional phot2 and inactivated phot1 molecules [7].
• Consistent with their different fluence rate sensitivities, phot1 and phot2 signaling pathways affected fitness at discrete life-cycle stages [6].
• We compared the fitness of wild-type, phot1, phot2, and nph3 genotypes over a range of light conditions in the field [6].
• The BL-induced Golgi localization of phot2 may be one of important signaling steps in the phot2 signal transduction pathway [8].

Anatomical context of PHOT2

• These results indicate that phot1 and phot2 mediate blue light-dependent activation of the plasma membrane H+-ATPase and illustrate that Arabidopsis guard cell protoplasts can be useful for biochemical analysis of stomatal functions [9].

Associations of PHOT2 with chemical compounds

• In all WT plants and in phot2 mutants, BL induced immediate Ca(2+) influx [5].
• Here we demonstrate that npl1, like nph1, noncovalently binds the chromophore flavin mononucleotide (FMN) within two specialized PAS domains, termed LOV domains [10].
• Phototropins (phot1 and phot2) are autophosphorylating serine/threonine kinases that function as photoreceptors for phototropism, light-induced chloroplast movement, and stomatal opening in Arabidopsis [11].
• Two blue light receptors in Arabidopsis, termed phot1 and phot2, which contain flavin chromophores and have intrinsic protein kinase activity, participate in several physiological processes [12].

Regulatory relationships of PHOT2

• Fitness costs of phot1 and nph3 were expressed mainly during seedling emergence from the soil whereas that of phot2 was expressed solely after emergence [6].

Other interactions of PHOT2

• There is evidence only for the phototropin blue light receptors (PHOT1 and PHOT2) in mediating blue light regulation of stomatal opening [13].
• Both the jac1 and phot2 mutants are defective in this chloroplast movement in darkness [14].

Analytical, diagnostic and therapeutic context of PHOT2

• These results unravel the stoma autonomous function in the blue light response and illuminate the implication of PHOT1 and/or PHOT2 in such response [15].
• Thus, these results suggest that phot1 and phot2 choose different signal transducers to induce three responses: phototropic response of hypocotyl, stomatal opening, and chloroplast relocation [16].
• These structural homologies indicate that NPH1 homologues can be grouped into two classes namely "NPH1 type" and "NPL1 type". Northern blot analysis showed that OsNPH1a was strongly expressed in coleoptiles, whereas OsNPH1b was highly expressed in leaves of dark-grown rice seedlings [17].

References