scholarly journals Catalytic Roles of Yeast GSK3β/Shaggy Homolog Rim11p in Meiotic Activation

Genetics ◽  
1999 ◽  
Vol 153 (3) ◽  
pp. 1145-1152
Author(s):  
Krishnamurthy Malathi ◽  
Yang Xiao ◽  
Aaron P Mitchell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Catalytic Activity ◽  
Protein Kinase ◽  
Complex Formation ◽  
Mutant Proteins ◽  
Tyrosine Residues ◽  
Low Level ◽  
Separable Functions

Abstract In Saccharomyces cerevisiae, many meiotic genes are activated by a heteromeric transcription factor composed of Ime1p and Ume6p. Ime1p-Ume6p complex formation depends upon the protein kinase Rim11p, which interacts with and phosphorylates both Ime1p and Ume6p in vitro. Rim11p may promote complex formation through its phosphorylation of Ime1p and Ume6p or simply through its interaction with both proteins. Here, we characterize mutant Ime1p derivatives that interact with Rim11p but are not phosphorylated in vitro. These mutant proteins are also defective in interaction with Ume6p. These results argue that Ime1p must be phosphorylated to interact with Ume6p. Our genetic observations suggest that Ime1p tyrosine residues are among the Rim11p phosphoacceptors, and we find that Ime1p reacts with an anti-phosphotyrosine antibody. Ime1p and Rim11p have been thought to act only through Ume6p, but we find that Ime1p and Rim11p promote meiosis at a very low level in the absence of Ume6p. A nonphosphorylatable mutant Ime1p derivative promotes sporulation through this Ume6p-independent pathway, as does a mutant Rim11p derivative that fails to interact with Ime1p. Therefore, Ime1p and Rim11p have two genetically separable functions in the sporulation program. However, catalytic activity of Rim11p is required for sporulation in the presence or absence of Ume6p.

scholarly journals Saccharomyces cerevisiae Yak1p protein kinase autophosphorylates on tyrosine residues and phosphorylates myelin basic protein on a C-terminal serine residue

2000 ◽  
Vol 348 (2) ◽  
pp. 263-272 ◽  
Author(s):  
Shouki KASSIS ◽  
Tiffany MELHUISH ◽  
Roland S. ANNAN ◽  
Susan L. CHEN ◽  
John C. LEE ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Catalytic Activity ◽  
Protein Kinase ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Full Length ◽  
Tandem Ms ◽  
Tyrosine Residues

The serine/threonine protein kinase, Yak1p, functions as a negative regulator of the cell cycle in Saccharomyces cerevisiae, acting downstream of the cAMP-dependent protein kinase. In the present work we report that overexpression of haemagglutinin-tagged full-lengthYak1p and an N-terminally truncated form (residues 148-807) lead to growth arrest in PKA compromised yak1 null yeast cells. Both forms of recombinant Yak1p kinase were catalytically active and preferred myelin basic protein (MBP) as a substrate over several other proteins. Phosphopeptide analysis of bovine MBP by tandem MS revealed two major Yak1p phosphorylation sites, Thr-97 and Ser-164. Peptides containing each site were obtained and tested as Yak1p substrates. Both forms of Yak1p phosphorylated a peptide containing the Ser-164 residue with far more efficient kinetics than MBP. The maximal velocity (Vmax) values of the full-length Yak1p reaction were 110±21 (Ser-164) and 8.7±1.7 (MBP), and those of N-terminally truncated Yak1p were 560.7±74.8 (Ser-164) and 34.4±2.2 (MBP) pmol/min per mg of protein. Although neither form of Yak1p was able to phosphorylate two generic protein tyrosine kinase substrates, both were phosphorylated on tyrosine residues in vivo and underwent tyrosine autophosphorylation when reacted with ATP in vitro. Tandem MS showed that Tyr-530 was phosphorylated both in vivo and in vitro after reaction with ATP. Pre-treatment with protein tyrosine phosphatase 1B removed all of Yak1p phosphotyrosine content and drastically reduced Yak1p activity against exogenous substrates, suggesting that the phosphotyrosine content of the enzyme is essential for its catalytic activity. Although the N-terminally truncated Yak1p was expressed at a lower level than the full-length protein, its catalytic activity and phosphotyrosine content were significantly higher than those of the full-length enzyme. Taken together, our results suggest that Yak1p is a dual specificity protein kinase which autophosphorylates on Tyr-530 and phosphorylates exogenous substrates on Ser/Thr residues.

scholarly journals OP0036 IL-6 ACTIVATES YES-ASSOCIATED PROTEIN (YAP) IN FIBROBLASTS AND INDUCES YAP-SNAIL COMPLEX FORMATION TO DRIVE SYNOVIAL LINING PATHOLOGY IN INFLAMMATORY ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 19.1-19
Author(s):  
R. Symons ◽  
F. Colella ◽  
F. Collins ◽  
A. Roelofs ◽  
C. De Bari
Keyword(s):  
Transcription Factor ◽  
Complex Formation ◽  
Inflammatory Arthritis ◽  
Normal Mouse ◽  
Joint Destruction ◽  
Proximity Ligation Assay ◽  
Synovial Lining ◽  
Arthritis Severity ◽  
Marginal Erosions

Background:In rheumatoid arthritis (RA), the fibroblast-like synoviocytes (FLS) in synovial lining become invasive and cause joint destruction. The molecular mechanisms underpinning this pathogenic FLS phenotype are incompletely understood. The FLS descend from Growth differentiation factor 5 (Gdf5)-expressing joint interzone cells in the embryo, and we showed that conditional ablation of the transcriptional co-activator Yes associated protein (Yap) in Gdf5-lineage cells prevents synovial lining hyperplasia after traumatic cartilage injury in mice [1].Objectives:Here, we investigated a potential role for Yap in pathogenic FLS in immune-mediated inflammatory arthritis.Methods:Immunohistochemistry was used to detect Yap in human RA synovium and Yap, Snail and Ctgf in mouse synovium following antigen-induced arthritis (AIA). To determine the effect of Yap knockout (KO) in synovial stromal cells, AIA was induced in Gdf5-Cre;tdTomato;Yapfl/fl (Yap cKO) and Gdf5-Cre;tdTomato;Yapwt/wt (control) mice, or in Pdgfrα-CreER;Yapfl/fl (Yap ciKO, targeting Pdgfrα-expressing fibroblasts) and Yapfl/fl or YapWT/fl (control) mice after adult tamoxifen induction. Yap KO in both models was confirmed by immunohistochemistry. After nine days, arthritis severity was determined by histological scoring of synovial lining hyperplasia, immune infiltrates, cellular exudate, and marginal erosions. TdTomato+ Gdf5-lineage cells in synovium were quantified. In vitro, Yap reporter cells were treated with inflammatory cytokines to evaluate their ability to stimulate Yap-induced GFP expression by flow cytometry. Snail overexpression, siRNA-mediated Yap knockdown, and IL-6/sIL-6R stimulation were performed on normal mouse FLS, AIA-FLS or human RA-FLS, and cell invasion through a matrigel-coated transwell was quantified. A proximity ligation assay was utilised to detect Yap/Snail complex formation.Results:Average expression levels of Yap (p<0.0001), its transcription factor partner Snail (p=0.002), and their downstream target Ctgf (p=0.0003), were increased in mouse synovium after AIA (n=5), and Yap was highly expressed by FLS in human RA synovium. Yap cKO mice (n=24) showed a significantly decreased arthritis severity (p=0.002) after AIA compared to controls (n=22), with significant reductions in synovial lining hyperplasia (p<0.001), synovial immune cell infiltrates (p=0.026) and marginal erosions (p=0.002). Similarly, Yap ciKO mice (n=6) showed a significant decrease in arthritis score (p=0.039) after AIA compared to controls (n=9). However, both control mice (p<0.001) and Yap cKO mice (p<0.001) showed an extensive expansion of tdTomato+ Gdf5-lineage synovial cells after AIA, with no significant difference between control and Yap cKO mice. In vitro, Yap knockdown prevented IL-6/sIL-6R-induced invasion of normal mouse FLS (p=0.037) and decreased the invasiveness of AIA-FLS (p=0.0057). Using Yap reporter cells, we found that Yap was activated by IL-6/sIL-6R (p=0.016), but not TNFα or IL-1β. Finally, IL-6/sIL-6R treatment of normal mouse FLS (p=0.033) or human RA-FLS (p=0.036) induced Yap-Snail complex formation, and Yap knockdown prevented FLS invasion induced by Snail overexpression (p=0.027).Conclusion:These data demonstrate that via activation by IL-6, and co-operation with the transcription factor Snail, Yap acts as a key modulator of the invasive and destructive phenotype of FLS in inflammatory arthritis. Therapeutic targeting of Yap could reduce joint destruction in RA.References:[1]A. J. Roelofs et al., “Joint morphogenetic cells in the adult mammalian synovium,” Nat. Commun., vol. 8, no. May, p. 15040, 2017. DOI: 10.1136/annrheumdis-2018-213799Acknowledgements:This work was funded by the Medical Research Council (MR/L020211/1 and MR/L022893/1) and Versus Arthritis (20775 and 21156).Disclosure of Interests:None declared

Mutational analysis of the Saccharomyces cerevisiae SNF1 protein kinase and evidence for functional interaction with the SNF4 protein

1989 ◽  
Vol 9 (11) ◽  
pp. 5034-5044
Author(s):  
J L Celenza ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Mutational Analysis ◽  
Gene Dosage ◽  
Regulatory System ◽  
Kinase Domain ◽  
Regulatory Function ◽  
Protein Kinase Activity ◽  
Glucose Limitation

The SNF1 gene of Saccharomyces cerevisiae encodes a protein-serine/threonine kinase that is required for derepression of gene expression in response to glucose limitation. We present evidence that the protein kinase activity is essential for SNF1 function: substitution of Arg for Lys in the putative ATP-binding site results in a mutant phenotype. A polyhistidine tract near the N terminus was found to be dispensable. Deletion of the large region C terminal to the kinase domain only partially impaired SNF1 function, causing expression of invertase to be somewhat reduced but still glucose repressible. The function of the SNF4 gene, another component of the regulatory system, was required for maximal in vitro activity of the SNF1 protein kinase. Increased SNF1 gene dosage partially alleviated the requirement for SNF4. C-terminal deletions of SNF1 also reduced dependence on SNF4. Our findings suggest that SNF4 acts as a positive effector of the kinase but does not serve a regulatory function in signaling glucose availability.

The C-terminal domain of Saccharomyces cerevisiae DNA topoisomerase II

1994 ◽  
Vol 14 (5) ◽  
pp. 3197-3207
Author(s):  
P R Caron ◽  
P Watt ◽  
J C Wang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Localization ◽  
Topoisomerase Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Mutant Proteins ◽  
Terminal Domain ◽  
Catalytically Active

A set of carboxy-terminal deletion mutants of Saccharomyces cerevisiae DNA topoisomerase II were constructed for studying the functions of the carboxyl domain in vitro and in vivo. The wild-type yeast enzyme is a homodimer with 1,429 amino acid residues in each of the two polypeptides; truncation of the C terminus to Ile-1220 has little effect on the function of the enzyme in vitro or in vivo, whereas truncations extending beyond Gln-1138 yield completely inactive proteins. Several mutant enzymes with C termini in between these two residues were found to be catalytically active but unable to complement a top2-4 temperature-sensitive mutation. Immunomicroscopy results suggest that the removal of a nuclear localization signal in the C-terminal domain is likely to contribute to the physiological dysfunction of these proteins; the ability of these mutant proteins to relax supercoiled DNA in vivo shows, however, that at least some of the mutant proteins are present in the nuclei in a catalytically active form. In contrast to the ability of the catalytically active mutant proteins to relax supercoiled intracellular DNA, all mutants that do not complement the temperature-dependent lethality and high frequency of chromosomal nondisjunction of top2-4 were found to lack decatenation activity in vivo. The plausible roles of the DNA topoisomerase II C-terminal domain, in addition to providing a signal for nuclear localization, are discussed in the light of these results.

scholarly journals Cloning and characterization of BCY1, a locus encoding a regulatory subunit of the cyclic AMP-dependent protein kinase in Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (4) ◽  
pp. 1371-1377 ◽  
Author(s):  
T Toda ◽  
S Cameron ◽  
P Sass ◽  
M Zoller ◽  
J D Scott ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Carbon Sources ◽  
Regulatory Subunit ◽  
Dependent Protein Kinase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Regulatory Subunits ◽  
Dependent Protein

We have cloned a gene (BCY1) from the yeast Saccharomyces cerevisiae that encodes a regulatory subunit of the cyclic AMP-dependent protein kinase. The encoded protein has a structural organization similar to that of the RI and RII regulatory subunits of the mammalian cyclic AMP-dependent protein kinase. Strains of S. cerevisiae with disrupted BCY1 genes do not display a cyclic AMP-dependent protein kinase in vitro, fail to grow on many carbon sources, and are exquisitely sensitive to heat shock and starvation.

Invariant phosphorylation of the Saccharomyces cerevisiae Cdc28 protein kinase

1988 ◽  
Vol 8 (7) ◽  
pp. 2976-2979
Author(s):  
J A Hadwiger ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Cycle Arrest ◽  
Phosphorylation Level ◽  
Proposed Regulation ◽  
Specific Protein Kinase

The phosphorylation level of the Saccharomyces cerevisiae Cdc28 protein remained invariant under conditions that resulted in cell cycle arrest in the G1 phase and loss of Cdc28-specific protein kinase activity when the activity was assayed in vitro. These results are in contrast to the proposed regulation of the homologous Cdc2 protein kinase of Schizosaccharomyces pombe.

14-3-3 Isotypes facilitate coupling of protein kinase C-ζ to Raf-1: negative regulation by 14-3-3 phosphorylation

2000 ◽  
Vol 345 (2) ◽  
pp. 297-306 ◽  
Author(s):  
Paulus C. J. VAN DER HOEVEN ◽  
José C. M. VAN DER WAL ◽  
Paula RUURS ◽  
Marc C. M. VAN DIJK ◽  
Wim J. VAN BLITTERSWIJK
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Complex Formation ◽  
Dependent Manner ◽  
Cos Cells ◽  
Kinase C ◽  
Pkc Ζ ◽  
Co Precipitation

14-3-3 Proteins may function as adapters or scaffold in signal-transduction pathways. We found previously that protein kinase C-ζ (PKC-ζ) can phosphorylate and activate Raf-1 in a signalling complex [van Dijk, Hilkmann and van Blitterswijk (1997) Biochem. J. 325, 303-307]. We report now that PKC-ζ-Raf-1 interaction is mediated by 14-3-3 proteins in vitro and in vivo. Co-immunoprecipitation experiments in COS cells revealed that complex formation between PKC-ζ and Raf-1 is mediated strongly by the 14-3-3β and -θ isotypes, but not by 14-3-3ζ. Far-Western blotting revealed that 14-3-3 binds PKC-ζ directly at its regulatory domain, where a S186A mutation in a putative 14-3-3-binding domain strongly reduced the binding and the complex formation with 14-3-3β and Raf-1. Treatment of PKC-ζ with lambda protein phosphatase also reduced its binding to 14-3-3β in vitro. Preincubation of an immobilized Raf-1 construct with 14-3-3β facilitated PKC-ζ binding. Together, the results suggest that 14-3-3 binds both PKC-ζ (at phospho-Ser-186) and Raf-1 in a ternary complex. Complex formation was much stronger with a kinase-inactive PKC-ζ mutant than with wild-type PKC-ζ, supporting the idea that kinase activity leads to complex dissociation. 14-3-3β and -θ were substrates for PKC-ζ, whereas 14-3-3ζ was not. Phosphorylation of 14-3-3β by PKC-ζ negatively regulated their physical association. 14-3-3β with its putative PKC-ζ phosphorylation sites mutated enhanced co-precipitation between PKC-ζ and Raf-1, suggesting that phosphorylation of 14-3-3 by PKC-ζ weakens the complex in vivo. We conclude that 14-3-3 facilitates coupling of PKC-ζ to Raf-1 in an isotype-specific and phosphorylation-dependent manner. We suggest that 14-3-3 is a transient mediator of Raf-1 phosphorylation and activation by PKC-ζ.

scholarly journals Molecular analysis of the SNF4 gene of Saccharomyces cerevisiae: evidence for physical association of the SNF4 protein with the SNF1 protein kinase.

1989 ◽  
Vol 9 (11) ◽  
pp. 5045-5054 ◽  
Author(s):  
J L Celenza ◽  
F J Eng ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Glucose Repression ◽  
Gene Dosage ◽  
Essential Gene ◽  
Glucose Deprivation ◽  
Protein Kinase Activity ◽  
Lacz Gene ◽  
Physical Association

The SNF4 gene is required for expression of glucose-repressible genes in response to glucose deprivation in Saccharomyces cerevisiae. Previous evidence suggested that SNF4 is functionally related to SNF1, another essential gene in this global regulatory system that encodes a protein kinase. Increased SNF1 gene dosage partially compensates for a mutation in SNF4, and the SNF4 function is required for maximal SNF1 protein kinase activity in vitro. We have cloned SNF4 and identified its 1.2-kilobase RNA, which is not regulated by glucose repression. A 36-kilodalton SNF4 protein is predicted from the nucleotide sequence. Disruption of the chromosomal SNF4 locus revealed that the requirement for SNF4 function is less stringent at low temperature (23 degrees C). A bifunctional SNF4-lacZ gene fusion that includes almost the entire SNF4 coding sequence was constructed. The fusion protein was shown by immunofluorescence microscopy to be distributed throughout the cell, with partial localization to the nucleus. The SNF4-beta-galactosidase protein coimmunoprecipitated with the SNF1 protein kinase, thus providing evidence for the physical association of the two proteins.

scholarly journals Analysis of the interaction between piD261/Bud32, an evolutionarily conserved protein kinase of Saccharomyces cerevisiae, and the Grx4 glutaredoxin

2004 ◽  
Vol 377 (2) ◽  
pp. 395-405 ◽  
Author(s):  
Raffaele LOPREIATO ◽  
Sonia FACCHIN ◽  
Geppo SARTORI ◽  
Giorgio ARRIGONI ◽  
Stefano CASONATO ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Hybrid Approach ◽  
Inosine Monophosphate Dehydrogenase ◽  
Gene Encoding ◽  
Putative Protease ◽  
Structural Homologues ◽  
Novel Protein

The Saccharomyces cerevisiae piD261/Bud32 protein and its structural homologues, which are present along the Archaea–Eukarya lineage, constitute a novel protein kinase family (the piD261 family) distantly related in sequence to the eukaryotic protein kinase superfamily. It has been demonstrated that the yeast protein displays Ser/Thr phosphotransferase activity in vitro and contains all the invariant residues of the family. This novel protein kinase appears to play an important cellular role as deletion in yeast of the gene encoding piD261/Bud32 results in the alteration of fundamental processes such as cell growth and sporulation. In this work we show that the phosphotransferase activity of Bud32 is relevant to its functionality in vivo, but is not the unique role of the protein, since mutants which have lost catalytic activity but not native conformation can partially complement the disruption of the gene encoding piD261/Bud32. A two-hybrid approach has led to the identification of several proteins interacting with Bud32; in particular a glutaredoxin (Grx4), a putative glycoprotease (Ykr038/Kae1) and proteins of the Imd (inosine monophosphate dehydrogenase) family seem most plausible interactors. We further demonstrate that Grx4 directly interacts with Bud32 and that it is phosphorylated in vitro by Bud32 at Ser-134. The functional significance of the interaction between Bud32 and the putative protease Ykr038/Kae1 is supported by its evolutionary conservation.

Sign in / Sign up

Export Citation Format

Share Document