Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cell cycle of eukaryotes is tightly regulated through the activity of cyclin-dependent kinases. The Arabidopsis thaliana CDKA;1 (CDC2aAt) gene is thought to encode such a protein kinase, since it is actively transcribed in proliferating tissues and can complement defects in the Schizosaccharomyces pombe cdc2 gene. We analyzed the functional structure of the CDKA;1 promoter, using fusion genes between various upstream regions of CDKA;1 and the Escherichia coli beta-glucuronidase (GUS) gene. A 595 bp DNA fragment upstream from the transcription start site conferred GUS activity on developing trichomes, but not on proliferating tissues. On the other hand, another upstream fragment extending to the 5' non-coding transcribed region gave GUS activity to both proliferating tissues and developing trichomes. Against the gl2 mutant background, GUS activity directed by the 595 bp fragment was detected in single-stalk cells, but not in giant cells without obvious polar extension growth. These results revealed that the 595 bp fragment lacks cis element(s) essential for proliferating-cell-specific promoter activity, but can direct transcription in a specific period during trichome development, which does not include cell division. This suggests that CDKA;1 functions during cell morphogenesis as well as cell proliferation.
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PMID:An upstream region of the Arabidopsis thaliana CDKA;1 (CDC2aAt) gene directs transcription during trichome development. 1144 60

A-type cyclin-dependent kinase (CDKA) is an ortholog of yeast Cdc2/Cdc28p, and is assumed to have an essential function in plant growth and organogenesis. Previous studies revealed that its kinase activity is controlled by post-translational modifications, such as binding to cyclins and phosphorylations, but its transcriptional regulation is poorly understood. Here, we generated a promoter dissection series of Arabidopsis (Arabidopsis thaliana) CDKA;1, and used beta-glucuronidase (GUS) gene-fused reporter constructs for expression analyses in planta. The results revealed two types of transcriptional control in shoots: general quantitative regulation and cell type-specific regulation. We identified a promoter region that promotes CDKA;1 expression in the leaf epidermis, but not in the L1 layer of the shoot apical meristem. This region also directed abaxial side-biased expression, which may be linked to the adaxial/abaxial side specification. Another reporter construct showed that CDKA;1 expression in the inner layers of leaves is controlled by a distinct regulatory region in the promoter. These results suggest that the transcriptional regulation of CDKA;1 may play a key role in proper development of leaves by coordinating cell division and differentiation of different cell types.
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PMID:Quantitative and cell type-specific transcriptional regulation of A-type cyclin-dependent kinase in Arabidopsis thaliana. 1928 89