scholarly journals G1 Transcription Factors Are Differentially Regulated in Saccharomyces cerevisiae by the Swi6-Binding Protein Stb1

2003 ◽  
Vol 23 (14) ◽  
pp. 5064-5077 ◽  
Author(s):  
Michael Costanzo ◽  
Oliver Schub ◽  
Brenda Andrews

ABSTRACT Stage-specific transcriptional programs are an integral feature of cell cycle regulation. In the budding yeast Saccharomyces cerevisiae, over 120 genes are coordinately induced in late G1 phase by two heterodimeric transcription factors called SBF and MBF. Activation of SBF and MBF is an upstream initiator of key cell cycle events, including budding and DNA replication. SBF and MBF regulation is complex and genetically redundant, and the precise mechanism of G1 transcriptional activation is unclear. Assays using SBF- and MBF-specific reporter genes revealed that the STB1 gene specifically affected MBF-dependent transcription. STB1 encodes a known Swi6-binding protein, but an MBF-specific function had not been previously suspected. Consistent with a specific role in regulating MBF, a STB1 deletion strain requires SBF for viability and microarray studies show a decrease in MBF-regulated transcripts in a swi4Δ mutant following depletion of Stb1. Chromatin immunoprecipitation experiments confirm that Stb1 localizes to promoters of MBF-regulated genes. Our data indicate that, contrary to previous models, MBF and SBF have unique components and might be distinctly regulated.

2009 ◽  
Vol 21 (1) ◽  
pp. 194
Author(s):  
N. Mtango ◽  
K. Latham

After fertilization, cell division is required for development during the transition from a zygote to an embryo. Degradation of oocyte transcripts, transcriptional activation of the nucleus, and chromatin remodeling occur during early cleavage divisions. Defects in cell cycle regulation decrease the ability of embryo to grow and can be detrimental. In the rhesus monkey, embryos derived by fertilization of oocytes from prepubertal females or oocytes collected during the non-breeding season undergo cleavage arrest (Schramm and Bavister 1994; Zheng et al. 2001). We employed the Primate Embryo Gene Expression Resource (PREGER; www.Preger.org) to examine the expression pattern of 70 mRNAs involved in cell cycle regulation in rhesus monkey oocytes and embryos derived from different stimulation protocols (non-stimulated, FSH stimulated-in vitro matured, and FSH and hCG stimulated-in vivo matured; Mtango and Latham 2007, 2008; Zheng et al. 2005). The resource encompasses a large, biologically rich set of more than 170 samples with 1 to 4 oocytes or embryos which were constructed using the quantitative amplification and dot blotting method. This method entails the direct lysis of small numbers of oocytes or embryos in a reverse transcription buffer supplemented with nonionic detergent, thereby avoiding RNA losses associated with organic extractions (Brady and Iscove 1993). We find that aberrant regulation of cell cycle regulatory gene mRNAs is a prominent feature of oocytes and embryos of compromised developmental potential (FSH stimulated-moderate reduced potential and NS-severely compromised potential). Of the 56 mRNAs for which expression was detected, there was significant aberrations related to oocyte and embryo quality in the expression of more than half (n = 30), P < 0.05), 26 of 30 display significant differences in metaphase II stage oocytes, 20 being altered in FSH stimulated females and 24 of 30 being altered in NS females. The comparison between monkey and previously reported mouse array expression data (Zeng et al. 2004) revealed striking differences between 2 species. These data provide novel information about disruptions in the expression of genes controlling the cell cycle in oocytes and embryos of compromised developmental potential. We thank Bela Patel, Malgorzata McMenamin, and Ann Marie Paprocki for their technical assistance. We also thank R. Dee Schramm for his contribution to the development of the PREGER resource. This work was supported by National Centers for Research Resources Grant RR-15253.


EMBO Reports ◽  
2006 ◽  
Vol 7 (5) ◽  
pp. 519-524 ◽  
Author(s):  
Hiroshi Yokoyama ◽  
Masaki Mizunuma ◽  
Michiyo Okamoto ◽  
Josuke Yamamoto ◽  
Dai Hirata ◽  
...  

2004 ◽  
Vol 101 (16) ◽  
pp. 6086-6091 ◽  
Author(s):  
M. Mizunuma ◽  
K. Miyamura ◽  
D. Hirata ◽  
H. Yokoyama ◽  
T. Miyakawa

Cell Cycle ◽  
2011 ◽  
Vol 10 (16) ◽  
pp. 2703-2713 ◽  
Author(s):  
Guodong Yang ◽  
Xiaozhao Lu ◽  
Li Wang ◽  
Yongqian Bian ◽  
Haiyan Fu ◽  
...  

1998 ◽  
Vol 18 (12) ◽  
pp. 7360-7370 ◽  
Author(s):  
Liang Cheng ◽  
Linda Hunke ◽  
Christopher F. J. Hardy

ABSTRACT Progression through and completion of mitosis require the actions of the evolutionarily conserved Polo kinase. We have determined that the levels of Cdc5p, a Saccharomyces cerevisiae member of the Polo family of mitotic kinases, are cell cycle regulated. Cdc5p accumulates in the nuclei of G2/M-phase cells, and its levels decline dramatically as cells progress through anaphase and begin telophase. We report that Cdc5p levels are sensitive to mutations in key components of the anaphase-promoting complex (APC). We have determined that Cdc5p-associated kinase activity is restricted to G2/M and that this activity is posttranslationally regulated. These results further link the actions of the APC to the completion of mitosis and suggest possible roles for Cdc5p during progression through and completion of mitosis.


1994 ◽  
Vol 14 (7) ◽  
pp. 4779-4787
Author(s):  
F R Cross ◽  
M Hoek ◽  
J D McKinney ◽  
A H Tinkelenberg

Expression of the Saccharomyces cerevisiae CLN1 and CLN2 genes is cell cycle regulated, and the genes may be controlled by positive feedback. It has been proposed that positive feedback operates via Cln/Cdc28 activation of the Swi4/Swi6 transcription factor, leading to CLN1 and CLN2 transcription due to Swi4 binding to specific sites (SCBs) in the CLN1 and CLN2 promoters. To test this proposal, we have examined the effects of deletion either of the potential SCBs in the CLN2 promoter or of the SWI4 gene on CLN2 transcriptional control. Deletion of a restriction fragment containing the identified SCBs from the promoter does not prevent cell cycle regulation of CLN2 expression, although expression is lowered at all cell cycle positions. A promoter containing a 5.5-kb plasmid insertion or an independent 2.5-kb insertion at the point of deletion of the SCB-containing restriction fragment also exhibits cell cycle regulation, so involvement of unidentified upstream SCBs is unlikely. Neither Swi4 nor the related Mbp1 transcription factor is required for cell cycle regulation of the intact CLN2 promoter. In contrast, Swi4 (but not Mbp1) is required for correct cell cycle regulation of the insertion/deletion promoter lacking SCB sites. We have extended previous genetic evidence for involvement of Swi4 in some aspect of CLN2 function: a mutant hunt for CLN2 positive regulatory factors yielded only swi4 mutations at saturation. Swi4 may bind to nonconsensus sequences in the CLN2 promoter (possibly in addition to consensus sites), or it may act indirectly to regulate CLN2 expression.


1995 ◽  
Vol 15 (5) ◽  
pp. 2509-2516 ◽  
Author(s):  
J D McKinney ◽  
F R Cross

Significant accumulation of Far1p is restricted to the G1 phase of the Saccharomyces cerevisiae cell cycle. Here we demonstrate yeast cell cycle regulation of Far1p proteolysis. Deletions within the 50 N-terminal amino acids of Far1p increase stability and reduce cell cycle regulation of Far1p abundance. Whereas wild-type Far1p specifically and exclusively promotes G1 phase arrest in response to mating factor, stabilized Far1p promoted arrest both during and after G1. The loss of the G1 specificity of Far1p action requires elimination of FAR1 transcriptional regulation (by means of the GAL1 promoter) as well as N-terminal truncation. Thus, the cell cycle specificity of mating factor arrest may be largely due to cell cycle regulation of FAR1 transcription and protein stability.


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