Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Feb 28;2(2):e249.
doi: 10.1371/journal.pone.0000249.

Control of signaling in a MAP-kinase pathway by an RNA-binding protein

Susanne Prinz  1 , Christine Aldridge, Stephen A Ramsey, R James Taylor, Timothy Galitski
Affiliations

Control of signaling in a MAP-kinase pathway by an RNA-binding protein

Susanne Prinz et al. PLoS One. .

Abstract

Signaling-protein mRNAs tend to have long untranslated regions (UTRs) containing binding sites for RNA-binding proteins regulating gene expression. Here we show that a PUF-family RNA-binding protein, Mpt5, represses the yeast MAP-kinase pathway controlling differentiation to the filamentous form. Mpt5 represses the protein levels of two pathway components, the Ste7 MAP-kinase kinase and the Tec1 transcriptional activator, and negatively regulates the kinase activity of the Kss1 MAP kinase. Moreover, Mpt5 specifically inhibits the output of the pathway in the absence of stimuli, and thereby prevents inappropriate cell differentiation. The results provide an example of what may be a genome-scale level of regulation at the interface of signaling networks and protein-RNA binding networks.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Repression of yeast filamentous-form phenotypes by MPT5.
(A–D) Diploid yeast were grown under yeast-form conditions (SCD liquid and SCD) or filamentous-form conditions (SLAD) and microscopically imaged. (E) Patches of yeast were grown on rich medium agar and subjected to a washing-off assay of adhesion.
Figure 2
Figure 2. In vivo TEC1 mRNA binding by Mpt5.
An immunoprecipitate of epitope-tagged Mpt5 protein was subjected to reverse transcription and gene-specific polymerase chain reaction to detect the presence of bound mRNAs. Control experiments lacked either the epitope tag or reverse transcriptase.
Figure 3
Figure 3. Repression of Ste7 and Tec1 protein levels by MPT5.
(A) Yeast strains were grown under yeast-form conditions. Protein extracts were analyzed by western blot, with Pgk serving as a loading control. (B) RNA extracts were analyzed by northern blot, with U3 serving as a loading control.
Figure 4
Figure 4. UTR sequences and repression by MPT5.
Yeast strains were grown under yeast-form conditions. Protein and RNA extracts were prepared and analyzed by (A) western blot and (B) northern blot. Pgk protein and U3 RNA served as loading controls.
Figure 5
Figure 5. Inhibition of Kss1-dependent phosophorylation of Ste7 by MPT5.
Yeast strains were grown under yeast-form conditions. Protein extracts were analyzed by western blot, with Pgk serving as a loading control. The effect of MPT5 deletion on Ste7 phosphorylation is independent of RAS2 and PHD1 (A) but depends on KSS1 (B).
Figure 6
Figure 6. Specific inhibition of fMAPK pathway output by MPT5.
(A) Diploid strains with either a minimal filamentation-MAPK-pathway output reporter (FRE-GFP) or a mating-MAPK reporter (PRE-GFP) and the indicated genotypes were grown under yeast-form conditions and subjected to flow cytofluorometry. (B) The morphology and fluorescence of MPT5+ and mpt5Δ diploid cells with FRE-GFP were imaged by transmitted light and confocal fluorescence microscopy.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Qi M, Elion EA. MAP kinase pathways. J Cell Sci. 2005;118:3569–3572. - PubMed
    1. Prinz S, Avila-Campillo I, Aldridge C, Srinivasan A, Dimitrov K, et al. Control of yeast filamentous-form growth by modules in an integrated molecular network. Genome Res. 2004;14:380–390. - PMC - PubMed
    1. Gimeno CJ, Ljungdahl PO, Styles CA, Fink GR. Unipolar cell divisions in the yeast S. cerevisiae lead to filamentous growth: regulation by starvation and RAS. Cell. 1992;68:1077–1090. - PubMed
    1. Rives AW, Galitski T. Modular organization of cellular networks. Proc Natl Acad Sci U S A. 2003;100:1128–1133. - PMC - PubMed
    1. Madhani HD, Styles CA, Fink GR. MAP kinases with distinct inhibitory functions impart signaling specificity during yeast differentiation. Cell. 1997;91:673–684. - PubMed

Publication types

MeSH terms

LinkOut - more resources