In this study, we isolated a WD40-repeat gene from Artemisia annua glandular trichomes. This gene shows 69.97% sequence similarity to Arabidopsis TTG1 at aminoacid level. Sub-cellular localization study shows that AaW...In this study, we isolated a WD40-repeat gene from Artemisia annua glandular trichomes. This gene shows 69.97% sequence similarity to Arabidopsis TTG1 at aminoacid level. Sub-cellular localization study shows that AaWD40 protein diffuses in both cell nucleus and cytosol. The correct nuclear localization of AaWD40 was observed when co-expressed with AabHLH, a putative A. thaliana AtTTG1 homologue cloned from Artemisia annua glandular trichomes. When AaWD40 gene was ectopically over expressed in Arabidopsis transparent testa glabrous1-1 (ttg1-1) mutants of A. thaliana, PAs production in seeds was restored, and the trichomeless phenotypes of mutant were rescued. Real-time PCR analysis results revealed that ETC1, CPC, TTG2 and BAN (the downstream targets of AtTTG1 depend on regulatory complex), which regulate the epidermal differentiation and anthocyanin biosynthesis were differentially expressed as a result of AaWD40 over expression. Furthermore, the CLV1, CLV2, CLV3 and WUS, which are required to maintain the stem-cell niche of Arabidopsis shoot apex, were also modulated by AaWD40 and Arabidopsis TTG1. The transcriptions of AP2/ERF, bHLH, MYB, WRKY and NACs family proteins, which are mostly involved in defense, stress response and development regulation, were remarkably modulated by AaWD40 over expression. We hypothesize that WD40 repeat proteins act as a crucial factor in regulating a wide variety of cellular functions in A. thaliana.展开更多
Phosphorylation of proteins is an important post-translational modification. Methods to determine the phosphorylation state of proteins are very important to evaluate diverse biological processes. CRK5 is the CDPK-rel...Phosphorylation of proteins is an important post-translational modification. Methods to determine the phosphorylation state of proteins are very important to evaluate diverse biological processes. CRK5 is the CDPK-related protein kinase in Arabidopsis, WD-repeat protein (WDRP) might be CRK5-interact-protein based on Y2H results. Here, we used bimolecular fluorescence complementation (BiFC) further to study and visualize the interaction between CRK5 and WDRP in living cells. Then, we combined Phos-tagTM SDS-PAGE with western blot (WB) analysis, using WDRP antibody and the anti-6×His antibody, to detect phosphorylated WDRP. This approach confirmed that WDRP might be phosphorylated by CRK5 in vitro. Site mutation analysis suggested that serine-70 might be the amino acid phosphorylated by CRK5 in WDRP. Cell extracts isolated from WT, OERK5, and crk5 used to analyze the kinase reaction using recombinant WDRP as substrate. These results demonstrated that WDRP was phosphorylated by cell extracts and that there may be additional kinases that phosphorylate WDRP in Arabidopsis. Phos-tagTM SDS-PAGE thus provides a suitable and convenient method for analysis of phosphorylation in plants.展开更多
文摘In this study, we isolated a WD40-repeat gene from Artemisia annua glandular trichomes. This gene shows 69.97% sequence similarity to Arabidopsis TTG1 at aminoacid level. Sub-cellular localization study shows that AaWD40 protein diffuses in both cell nucleus and cytosol. The correct nuclear localization of AaWD40 was observed when co-expressed with AabHLH, a putative A. thaliana AtTTG1 homologue cloned from Artemisia annua glandular trichomes. When AaWD40 gene was ectopically over expressed in Arabidopsis transparent testa glabrous1-1 (ttg1-1) mutants of A. thaliana, PAs production in seeds was restored, and the trichomeless phenotypes of mutant were rescued. Real-time PCR analysis results revealed that ETC1, CPC, TTG2 and BAN (the downstream targets of AtTTG1 depend on regulatory complex), which regulate the epidermal differentiation and anthocyanin biosynthesis were differentially expressed as a result of AaWD40 over expression. Furthermore, the CLV1, CLV2, CLV3 and WUS, which are required to maintain the stem-cell niche of Arabidopsis shoot apex, were also modulated by AaWD40 and Arabidopsis TTG1. The transcriptions of AP2/ERF, bHLH, MYB, WRKY and NACs family proteins, which are mostly involved in defense, stress response and development regulation, were remarkably modulated by AaWD40 over expression. We hypothesize that WD40 repeat proteins act as a crucial factor in regulating a wide variety of cellular functions in A. thaliana.
文摘Phosphorylation of proteins is an important post-translational modification. Methods to determine the phosphorylation state of proteins are very important to evaluate diverse biological processes. CRK5 is the CDPK-related protein kinase in Arabidopsis, WD-repeat protein (WDRP) might be CRK5-interact-protein based on Y2H results. Here, we used bimolecular fluorescence complementation (BiFC) further to study and visualize the interaction between CRK5 and WDRP in living cells. Then, we combined Phos-tagTM SDS-PAGE with western blot (WB) analysis, using WDRP antibody and the anti-6×His antibody, to detect phosphorylated WDRP. This approach confirmed that WDRP might be phosphorylated by CRK5 in vitro. Site mutation analysis suggested that serine-70 might be the amino acid phosphorylated by CRK5 in WDRP. Cell extracts isolated from WT, OERK5, and crk5 used to analyze the kinase reaction using recombinant WDRP as substrate. These results demonstrated that WDRP was phosphorylated by cell extracts and that there may be additional kinases that phosphorylate WDRP in Arabidopsis. Phos-tagTM SDS-PAGE thus provides a suitable and convenient method for analysis of phosphorylation in plants.
