Distinct cyclin genes define each stage of ciliate conjugation

Swi4 and Swi6 form a complex which is required for Start-dependent activation of HO and for high-level expression of G1 cyclin genes CLN1 and CLN2. To identify other regulators of this pathway, we screened for dominant, recessive, conditional, and allele-specific suppressors of swi4 mutants. We isolated 16 recessive suppressors that define three genes, SSF1, SSF5, and SSF9 (suppressor of swi four). Mutations in all three genes bypass the requirement for both Swi4 and Swi6 for HO transcription and activate transcription from reporter genes lacking upstream activating sequences (UASs). SSF5 is allelic with SIN4 (TSF3), a gene implicated in global repression of transcription and chromatin structure, and SSF9 is likely to be a new global repressor of transcription. SSF1 is allelic with CDC68 (SPT16). cdc68 mutations have been shown to increase expression from defective promoters, while preventing transcription from other intact promoters, including CLN1 and CLN2. We find that CDC68 is a required activator of both SWI4 and SWI6, suggesting that CDC68's role at the CLN promoters may be indirect. The target of CDC68 within the SWI4 promoter is complex in that known activating elements (MluI cell cycle boxes) in the SWI4 promoter are required for CDC68 dependence but only within the context of the full-length promoter. This result suggests that there may be both a chromatin structure and a UAS-specific component to Cdc68 function at SWI4. We suggest that Cdc68 functions both in the assembly of repressive complexes that form on many intact promoters in vivo and in the relief of this repression during gene activation.

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Identification of Arabidopsis Meiotic Cyclins Reveals Functional Diversification among Plant Cyclin Genes

PLoS Genetics ◽

10.1371/journal.pgen.1003508 ◽

2013 ◽

Vol 9 (5) ◽

pp. e1003508 ◽

Cited By ~ 32

Author(s):

Petra Bulankova ◽

Svetlana Akimcheva ◽

Nicole Fellner ◽

Karel Riha

Keyword(s):

Functional Diversification ◽

Plant Cyclin ◽

Cyclin Genes

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The Expression of D-Cyclin Genes Defines Distinct Developmental Zones in Snapdragon Apical Meristems and Is Locally Regulated by the Cycloidea Gene

PLANT PHYSIOLOGY ◽

10.1104/pp.122.4.1137 ◽

2000 ◽

Vol 122 (4) ◽

pp. 1137-1148 ◽

Cited By ~ 112

Author(s):

Valérie Gaudin ◽

Patricia A. Lunness ◽

Pierre R. Fobert ◽

Matthew Towers ◽

Catherine Riou-Khamlichi ◽

...

Keyword(s):

Apical Meristems ◽

Cyclin Genes

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Differential effects of Cdc68 on cell cycle-regulated promoters in Saccharomyces cerevisiae.

Molecular and Cellular Biology ◽

10.1128/mcb.14.11.7455 ◽

1994 ◽

Vol 14 (11) ◽

pp. 7455-7465 ◽

Cited By ~ 31

Author(s):

D Lycan ◽

G Mikesell ◽

M Bunger ◽

L Breeden

Keyword(s):

Cell Cycle ◽

Chromatin Structure ◽

Gene Activation ◽

High Level Expression ◽

Specific Component ◽

Allele Specific ◽

High Level ◽

Cyclin Genes ◽

Regulated Promoters

Swi4 and Swi6 form a complex which is required for Start-dependent activation of HO and for high-level expression of G1 cyclin genes CLN1 and CLN2. To identify other regulators of this pathway, we screened for dominant, recessive, conditional, and allele-specific suppressors of swi4 mutants. We isolated 16 recessive suppressors that define three genes, SSF1, SSF5, and SSF9 (suppressor of swi four). Mutations in all three genes bypass the requirement for both Swi4 and Swi6 for HO transcription and activate transcription from reporter genes lacking upstream activating sequences (UASs). SSF5 is allelic with SIN4 (TSF3), a gene implicated in global repression of transcription and chromatin structure, and SSF9 is likely to be a new global repressor of transcription. SSF1 is allelic with CDC68 (SPT16). cdc68 mutations have been shown to increase expression from defective promoters, while preventing transcription from other intact promoters, including CLN1 and CLN2. We find that CDC68 is a required activator of both SWI4 and SWI6, suggesting that CDC68's role at the CLN promoters may be indirect. The target of CDC68 within the SWI4 promoter is complex in that known activating elements (MluI cell cycle boxes) in the SWI4 promoter are required for CDC68 dependence but only within the context of the full-length promoter. This result suggests that there may be both a chromatin structure and a UAS-specific component to Cdc68 function at SWI4. We suggest that Cdc68 functions both in the assembly of repressive complexes that form on many intact promoters in vivo and in the relief of this repression during gene activation.

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3′ non-translated sequences in Drosophila cyclin B transcripts direct posterior pole accumulation late in oogenesis and peri-nuclear association in syncytial embryos

Development ◽

10.1242/dev.115.4.989 ◽

1992 ◽

Vol 115 (4) ◽

pp. 989-997 ◽

Cited By ~ 7

Author(s):

B. Dalby ◽

D.M. Glover

Keyword(s):

Untranslated Region ◽

Cyclin A ◽

Posterior Pole ◽

The Body ◽

Cyclin B ◽

Nurse Cells ◽

Nuclear Localisation ◽

Oocyte Cytoplasm ◽

Nuclear Association ◽

Cyclin Genes

We have characterised forms of the Drosophila cyclin B transcript that differ as a result of a splicing event which removes a nucleotide segment from the 3′ untranslated region. In oogenesis, both cyclin A RNA and a shorter form of the cyclin B transcript are seen in the cells of the germarium that are undergoing mitosis. The shorter cyclin B transcript alone is then detectable in the presumptive oocyte until stages 7–8 of oogenesis. Both cyclin A RNA and a longer form of the cyclin B RNA are then synthesised in the nurse cells during stages 9–11, to be deposited in the oocyte during stages 11–12. These transcripts become evenly distributed throughout the oocyte cytoplasm but, in addition, those of cyclin B become concentrated at the posterior pole. Examination of the distributions of RNAs transcribed from chimeric cyclin genes indicates that sequences in the 3′ untranslated region of the larger cyclin B RNA are required both for it to become concentrated at the posterior pole and to direct those transcripts in the body of the syncytial embryo to their peri-nuclear localisation. These sequences are disrupted by the splicing event which generates smaller cyclin B transcripts.

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Faculty Opinions recommendation of Identification of Arabidopsis meiotic cyclins reveals functional diversification among plant cyclin genes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718009536.793476576 ◽

2013 ◽

Author(s):

Lieven De Veylder

Keyword(s):

Functional Diversification ◽

Plant Cyclin ◽

Cyclin Genes

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A Novel cis-Acting Element in Promoters of Plant B-Type Cyclin Genes Activates M Phase–Specific Transcription

The Plant Cell ◽

10.1105/tpc.10.3.331 ◽

1998 ◽

Vol 10 (3) ◽

pp. 331-341 ◽

Cited By ~ 32

Author(s):

Masaki Ito ◽

Masayuki Iwase ◽

Hiroaki Kodama ◽

Philippe Lavisse ◽

Atsushi Komamine ◽

...

Keyword(s):

Cis Acting ◽

M Phase ◽

Cyclin Genes

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Expression pattern of tobacco cyclin genes

Plant Cell Reports ◽

10.1007/s002990050241 ◽

1997 ◽

Vol 16 (6) ◽

pp. 368-372

Author(s):

Y. Y. Setiady ◽

M. Sekine ◽

T. Yamamoto ◽

H. Kouchi ◽

A. Shinmyo

Keyword(s):

Expression Pattern ◽

Cyclin Genes

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Genome-Wide Analysis of the Cyclin Gene Family and Their Expression Profile in Medicago truncatula

International Journal of Molecular Sciences ◽

10.3390/ijms21249430 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9430

Author(s):

Juan Meng ◽

Mengdi Peng ◽

Jie Yang ◽

Yiran Zhao ◽

Junshu Hu ◽

...

Keyword(s):

Cell Cycle ◽

Gene Family ◽

Medicago Truncatula ◽

Nodule Development ◽

Nod Factor ◽

Genome Wide Analysis ◽

Genome Wide ◽

Cyclin Gene ◽

Legume Plants ◽

Cyclin Genes

Cyclins, together with highly conserved cyclin-dependent kinases (CDKs), play an important role in the process of cell cycle in plants, but less is known about the functions of cyclins in legume plants, especially Medicago truncatula. Our genome-wide analysis identified 58, 103, and 51 cyclin members in the M. truncatula, Glycine max, and Phaseolus vulgaris genomes. Phylogenetic analysis suggested that these cyclins could be classified into 10 types, and the CycB-like types (CycBL1-BL8) were the specific subgroups in M. truncatula, which was one reason for the expansion of the B-type in M. truncatula. All putative cyclin genes were mapped onto their own chromosomes of each genome, and 9 segmental duplication gene pairs involving 20 genes were identified in M. truncatula cyclins. Determined by quantitative real-time PCR, the expression profiling suggested that 57 cyclins in M. truncatula were differentially expressed in 9 different tissues, while a few genes were expressed in some specific tissues. Using the publicly available RNAseq data, the expression of Mtcyclins in the wild-type strain A17 and three nodule mutants during rhizobial infection showed that 23 cyclins were highly upregulated in the nodulation (Nod) factor-hypersensitive mutant sickle (skl) mutant after 12 h of rhizobium inoculation. Among these cyclins, six cyclin genes were also specifically expressed in roots and nodules, which might play specific roles in the various phases of Nod factor-mediated cell cycle activation and nodule development. Our results provide information about the cyclin gene family in legume plants, serving as a guide for further functional research on plant cyclins.

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