A small GTP-binding protein from Arabidopsis thaliana functionally complements the yeast YPT6 null mutant
| Autor: | Martin R. Schroeder, Dieter Gallwitz, T. L. Reynolds, Natasha V. Raikhel, Ludger Hengst, Sebastian Y. Bednarek, R. Grabowski |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: |
Saccharomyces cerevisiae Proteins
GTP' Physiology Molecular Sequence Data Arabidopsis Plant Science medicine.disease_cause Homology (biology) Fungal Proteins GTP-Binding Proteins Complementary DNA Protein targeting Schizosaccharomyces Genetics medicine Humans Amino Acid Sequence Cloning Molecular Peptide sequence Monomeric GTP-Binding Proteins biology Sequence Homology Amino Acid cDNA library Binding protein fungi Cell Membrane Genetic Complementation Test food and beverages biology.organism_classification Blotting Northern Blotting Southern Biochemistry Mutation Research Article |
| Popis: | A clone designated A.t.RAB6 encoding a small GTP-binding protein was isolated from a cDNA library of Arabidopsis thaliana leaf tissue. The predicted amino acid sequence was highly homologous to the mammalian and yeast counterparts, H.Rab6 and Ryh1/Ypt6, respectively. Lesser homology was found between the predicted Arabidopsis protein sequence and two small GTP-binding proteins isolated from plant species (44% homology to Zea mays Ypt1 and 43% homology to Nicotiana tabacum Rab5). Conserved stretches in the deduced amino acid sequence of A.t.Rab6 include four regions involved in GTP-binding, an effector region, and C-terminal cysteine residues required for prenylation and subsequent membrane attachment. Northern blot analysis demonstrated that A.t.Rab6 mRNA was expressed in root, leaf, stem, and flower tissues from A. thaliana with the highest levels present in roots. Escherichia coli produced histidine-tagged A.t.Rab6 protein-bound GTP, whereas a mutation in one of the guanine nucleotide-binding sites (asparagine122 to isoleucine) rendered it incapable of binding GTP. Functionally, the A.t.RAB6 gene was able to complement the temperature-sensitive phenotype of the YPT6 null mutant in yeast. The isolation of this gene will aid in the dissection of the machinery involved in soluble protein sorting at the trans-Golgi network of plants. |
| Databáze: | OpenAIRE |
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