The D-type alfalfa cyclin gene cycMs4 complements G1 cyclin-deficient yeast and is induced in the G1 phase of the cell cycle

• Published in: The Plant cell Vol. 7; no. 11; pp. 1847 - 1857
• Main Authors: Dahl, Marlis, Meskiene, Irute, Bögre, Laszlo, Dang Thi Cam Ha, Swoboda, Ines, Hubmann, Rainer, Hirt, Heribert, Heberle-Bors, Erwin
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Physiologists 01.11.1995
• Subjects: adn; Alfalfa; Amino Acid Sequence; arn mensajero; arn messager; Base Sequence; binding proteins; cell culture; Cell cycle; Cell Cycle - physiology; cell division; chemical composition; composicion quimica; composition chimique; cultivo de celulas; culture de cellule; Cyclins; Cyclins - biosynthesis; Cyclins - genetics; division cellulaire; division celular; dna; expresion genica; expression des genes; G1 Phase; Gels; gene; Gene Expression; gene transfer; Genes; Genes, Plant; Genetic Complementation Test; genetic transformation; genetica; genetics; genetique; Histones; Interphase; medicago sativa; Medicago sativa - cytology; Medicago sativa - genetics; Medicago sativa - metabolism; Meristem; meristemas; meristeme; meristems; messenger rna; Molecular Sequence Data; mutant; mutantes; mutants; nucleotide sequence; Plant cells; Plant Proteins; proteinas aglutinantes; proteine de liaison; racine; raices; Recombinant Proteins - biosynthesis; RNA; RNA, Plant - isolation & purification; RNA, Plant - metabolism; roots; saccharomyces cerevisiae; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; secuencia nucleica; sequence nucleique; transferencia de genes; transfert de gene; transformacion genetica; transformation genetique; Yeasts
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.7.11.1847

Cyclins are key regulators of the cell cycle in all eukaryotes. In alfalfa, we have previously isolated three B-type cyclins. The closely related cycMs1 and cycMs2 genes are expressed primarily during the G2 and M phases and are most likely mitotic cycling; expression of the cycMs3 gene is induced in the G0-to-G1 transition, when cells reenter the cell cycle. By complementation of G1 cyclin-deficient yeast cells, a novel alfalfa cyclin, designated cycMs4, was isolated. The predicted amino acid sequence of the cycMs4 gene is most similar to that of the Arabidopsis cyclin delta 3 gene. CycMs4 and cyclin delta 3 belong to the class of D-type cyclins and contain PEST-rich regions and a retinoblastoma binding motif. When comparing expression levels in different organs, cycMs4 transcripts were present predominantly in roots. Whereas expression of the cycMs4 gene was cell cycle-regulated in suspension-cultured cells, transcription in roots was observed to depend also on the positional context of the cell. When differentiated G0-arrested leaf cells were induced to resume cell division by treatment with plant hormones, cycMs4 transcription was induced before the onset of DNA synthesis. Whereas this induction was preceded by that of the cycMs3 gene, cycMs2 expression occurred later and at the same time as mitotic activity. These data suggest that cycMs4 plays a role in the G1-to-S transition and provide a model to investigate the plant cell cycle at the molecular level.