Distinct classes of mitotic cyclins are differentially expressed in the soybean shoot apex during the cell cycle.
AUTOR(ES)
Kouchi, H
RESUMO
Protein phosphorylation by the complexes of cyclin and cyclin-dependent kinase plays a key role in cell cycle progression in all eukaryotes. The amplification by polymerase chain reaction of a cyclin box from developing root nodules and root apices of soybean showed the expression of a number of different molecular species of mitotic cyclins in plant meristems, and they were classified into five distinct groups based on their sequence similarities. The complete soybean cyclin cDNAs, cyc1Gm to cyc5Gm, corresponding to each group were isolated, and their predicted amino acid sequences showed clear similarities to mitotic cyclins identified from various organisms. These genes are expressed predominantly in such meristematic tissues as root and shoot apices and young developing nodules. Double-target in situ hybridization involving histone H4 as an S-phase marker allowed us to estimate the phases during which these cyclin genes are abundantly expressed. The results indicated that cyc5Gm is expressed in G2-to-M phases and cyc3Gm is expressed from late S-to-G2 phases. These expression patterns, together with the sequence criteria, strongly suggest that cyc3Gm and cyc5Gm encode the plant cognates for A- and B-type cyclins, respectively. In addition, the expression of cyc1Gm was restricted during a short period in S phase, suggesting that it belongs to a novel class of plant cyclins. Sequence comparison of 18 plant mitotic cyclins cloned thus far showed that they can be divided into four distinct structural groups with different functions in cell cycle progression.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=160940Documentos Relacionados
- Three discrete classes of Arabidopsis cyclins are expressed during different intervals of the cell cycle.
- Distinct classes of cdc2-related genes are differentially expressed during the cell division cycle in plants.
- Kunitz trypsin inhibitor genes are differentially expressed during the soybean life cycle and in transformed tobacco plants.
- Identification of genes expressed in the tobacco shoot apex during the floral transition.
- Photosynthetic Genes of Petunia (Mitchell) Are Differentially Expressed during the Diurnal Cycle