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)

Two protein kinase genes (atpk1 and atpk2) were isolated from Arabidopsis thaliana genomic DNA with a probe generated by polymerase chain reaction (PCR) using oligonucleotide primers encoding conserved eukaryotic protein kinase sequences. atpk1 and atpk2 are organized in a head-to-tail tandem array on chromosome 3 and have about 80% nucleotide sequence identity. atpk1 encodes a hydrophilic polypeptide of 465 amino acids, M(r) = 52,554. The centrally located catalytic domain contains all the conserved residues characteristic of eukaryotic protein kinases, with greatest similarity to the catalytic domains of 70-kDa ribosomal S6 protein kinase, protein kinase C, and protein kinase A. The C-terminal 75 residues also show homology to protein kinase C and S6 protein kinase. In contrast, the N-terminal 130 residues have no homology to any known protein, and thus may represent a new class of protein kinase regulatory domain. Other motifs found in the Atpk1 protein include two putative autophosphorylation sites, a pseudosubstrate site, two acidic domains, a lysine-rich domain, and two putative PEST sequences, which may contribute to the regulation of protein kinase activity. RNA-blot hybridization showed that atpk1 encoded a 1.8-kb mRNA. Analysis of atpk1 promoter/beta-glucuronidase reporter gene fusions in transgenic plants showed that atpk1 was expressed in all tissues and at all developmental stages, with the strongest expression observed in metabolically active tissues, suggesting that atpk1 is involved in the control of plant growth and development. The first intron of atpk1 functions as an enhancer in atpk1 expression.
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PMID:atpk1, a novel ribosomal protein kinase gene from Arabidopsis. I. Isolation, characterization, and expression. 791 97

Tuberization in potato is controlled by hormonal and environmental signals. Ca(2+), an important intracellular messenger, and calmodulin (CaM), one of the primary Ca(2+) sensors, have been implicated in controlling diverse cellular processes in plants including tuberization. The regulation of cellular processes by CaM involves its interaction with other proteins. To understand the role of Ca(2+)/CaM in tuberization, we have screened an expression library prepared from developing tubers with biotinylated CaM. This screening resulted in isolation of a cDNA encoding a novel CaM-binding protein (potato calmodulin-binding protein (PCBP)). Ca(2+)-dependent binding of the cDNA-encoded protein to CaM is confirmed by (35)S-labeled CaM. The full-length cDNA is 5 kb long and encodes a protein of 1309 amino acids. The deduced amino acid sequence showed significant similarity with a hypothetical protein from another plant, Arabidopsis. However, no homologs of PCBP are found in nonplant systems, suggesting that it is likely to be specific to plants. Using truncated versions of the protein and a synthetic peptide in CaM binding assays we mapped the CaM-binding region to a 20-amino acid stretch (residues 1216-1237). The bacterially expressed protein containing the CaM-binding domain interacted with three CaM isoforms (CaM2, CaM4, and CaM6). PCBP is encoded by a single gene and is expressed differentially in the tissues tested. The expression of CaM, PCBP, and another CaM-binding protein is similar in different tissues and organs. The predicted protein contained seven putative nuclear localization signals and several strong PEST motifs. Fusion of the N-terminal region of the protein containing six of the seven nuclear localization signals to the reporter gene beta-glucuronidase targeted the reporter gene to the nucleus, suggesting a nuclear role for PCBP.
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PMID:Isolation and characterization of a novel calmodulin-binding protein from potato. 1168 78