Intragenic suppressor mutations of the COQ8 protein kinase homolog restore coenzyme Q biosynthesis and function in Saccharomyces cerevisiae

ABSTRACT It was recently discovered that the aarF gene inProvidencia stuartii is required for coenzyme Q (CoQ) biosynthesis. Here we report that yigR, theEscherichia coli homologue of aarF, isubiB, a gene required for the first monooxygenase step in CoQ biosynthesis. Both the P. stuartii aarF and E. coli ubiB (yigR) disruption mutant strains lack CoQ and accumulate octaprenylphenol. Octaprenylphenol is the CoQ biosynthetic intermediate found to accumulate in the E. coli strain AN59, which contains the ubiB409 mutant allele. Analysis of the mutation in the E. coli strain AN59 reveals no mutations within the ubiB gene, but instead shows the presence of an IS1 element at position +516 of the ubiE gene. The ubiE gene encodes aC-methyltransferase required for the synthesis of both CoQ and menaquinone, and it is the 5′ gene in an operon containingubiE, yigP, and ubiB. The data indicate that octaprenylphenol accumulates in AN59 as a result of a polar effect of the ubiE::IS1mutation on the downstream ubiB gene. AN59 is complemented by a DNA segment containing the contiguous ubiE,yigP, and ubiB genes. Although transformation of AN59 with a DNA segment containing the ubiB coding region fails to restore CoQ biosynthesis, transformation with theubiE coding region results in a low-frequency but significant rescue attributed to homologous recombination. In addition, the fre gene, previously considered to correspond toubiB, was found not to be involved in CoQ biosynthesis. TheubiB gene is a member of a predicted protein kinase family of which the Saccharomyces cerevisiae ABC1 gene is the prototypic member. The possible protein kinase function of UbiB and Abc1 and the role these polypeptides may play in CoQ biosynthesis are discussed.

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Pag1p, a Novel Protein Associated with Protein Kinase Cbk1p, Is Required for Cell Morphogenesis and Proliferation inSaccharomyces cerevisiae

Molecular Biology of the Cell ◽

10.1091/mbc.01-07-0365 ◽

2002 ◽

Vol 13 (2) ◽

pp. 503-514 ◽

Cited By ~ 75

Author(s):

Li-Lin Du ◽

Peter Novick

Keyword(s):

Saccharomyces Cerevisiae ◽

Protein Kinase ◽

Rna Binding ◽

Rna Binding Protein ◽

Biological Processes ◽

Cell Morphogenesis ◽

Gene Encoding ◽

And Function ◽

Genetic Results ◽

Novel Protein

Protein kinases in the Cot-1/Orb6/Ndr/Warts family are important regulators of cell morphogenesis and proliferation. Cbk1p, a member of this family in Saccharomyces cerevisiae, has previously been shown to be required for normal morphogenesis in vegetatively growing cells and in haploid cells responding to mating pheromone. A mutant of PAG1, a novel gene in S. cerevisiae, displayed defects similar to those ofcbk1 mutants. pag1 andcbk1 mutants share a common set of suppressors, including the disruption of SSD1, a gene encoding an RNA binding protein, and the overexpression of Sim1p, an extracellular protein. These genetic results suggest that PAG1 andCBK1 act in the same pathway. Furthermore, we found that Pag1p and Cbk1p localize to the same polarized peripheral sites and that they coimmunoprecipitate with each other. Pag1p is a conserved protein. The homologs of Pag1p in other organisms are likely to form complexes with the Cbk1p-related kinases and function with those kinases in the same biological processes.

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Spatial control of actin-based motility through plasmalemmal PtdIns(4,5)P2-rich raft assemblies.

Biochemical Society Symposium ◽

10.1042/bss0720119 ◽

2005 ◽

Vol 72 ◽

pp. 119-127 ◽

Cited By ~ 19

Author(s):

Tamara Golub ◽

Caroni Pico

Keyword(s):

Protein Kinase ◽

Cell Surface ◽

Actin Cytoskeleton ◽

Lipid Rafts ◽

Patch Clustering ◽

Pkc Protein Kinase C ◽

Membrane Bound ◽

And Function ◽

Cytoskeleton Dynamics ◽

Syndrome Protein

The interactions of cells with their environment involve regulated actin-based motility at defined positions along the cell surface. Sphingolipid- and cholesterol-dependent microdomains (rafts) order proteins at biological membranes, and have been implicated in most signalling processes at the cell surface. Many membrane-bound components that regulate actin cytoskeleton dynamics and cell-surface motility associate with PtdIns(4,5)P2-rich lipid rafts. Although raft integrity is not required for substrate-directed cell spreading, or to initiate signalling for motility, it is a prerequisite for sustained and organized motility. Plasmalemmal rafts redistribute rapidly in response to signals, triggering motility. This process involves the removal of rafts from sites that are not interacting with the substrate, apparently through endocytosis, and a local accumulation at sites of integrin-mediated substrate interactions. PtdIns(4,5)P2-rich lipid rafts can assemble into patches in a process depending on PtdIns(4,5)P2, Cdc42 (cell-division control 42), N-WASP (neural Wiskott-Aldrich syndrome protein) and actin cytoskeleton dynamics. The raft patches are sites of signal-induced actin assembly, and their accumulation locally promotes sustained motility. The patches capture microtubules, which promote patch clustering through PKA (protein kinase A), to steer motility. Raft accumulation at the cell surface, and its coupling to motility are influenced greatly by the expression of intrinsic raft-associated components that associate with the cytosolic leaflet of lipid rafts. Among them, GAP43 (growth-associated protein 43)-like proteins interact with PtdIns(4,5)P2 in a Ca2+/calmodulin and PKC (protein kinase C)-regulated manner, and function as intrinsic determinants of motility and anatomical plasticity. Plasmalemmal PtdIns(4,5)P2-rich raft assemblies thus provide powerful organizational principles for tight spatial and temporal control of signalling in motility.

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Faculty Opinions recommendation of Protein kinase A, TOR, and glucose transport control the response to nutrient repletion in Saccharomyces cerevisiae.

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

10.3410/f.13484976.14862094 ◽

2012 ◽

Author(s):

Christopher Loewen

Keyword(s):

Saccharomyces Cerevisiae ◽

Protein Kinase ◽

Protein Kinase A ◽

Glucose Transport ◽

Transport Control ◽

Kinase A

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Faculty Opinions recommendation of KN-93, an inhibitor of calcium/calmodulin-dependent protein kinase IV, promotes generation and function of Foxp3⁺ regulatory T cells in MRL/lpr mice.

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

10.3410/f.718388824.793528888 ◽

2017 ◽

Author(s):

Theresa Lu ◽

William Shipman ◽

Dragos Dasoveanu

Keyword(s):

T Cells ◽

Protein Kinase ◽

Regulatory T Cells ◽

Dependent Protein Kinase ◽

Calcium Calmodulin Dependent ◽

Dependent Protein ◽

And Function

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The SRS2 suppressor of rad6 mutations of Saccharomyces cerevisiae acts by channeling DNA lesions into the RAD52 DNA repair pathway.

Genetics ◽

10.1093/genetics/124.4.817 ◽

1990 ◽

Vol 124 (4) ◽

pp. 817-831 ◽

Cited By ~ 6

Author(s):

R H Schiestl ◽

S Prakash ◽

L Prakash

Keyword(s):

Saccharomyces Cerevisiae ◽

Dna Repair ◽

Gamma Ray ◽

Dna Lesions ◽

Recombinational Repair ◽

Repair Pathway ◽

Uv Mutagenesis ◽

Uv Sensitivity ◽

Suppressor Mutations ◽

Induced Mutagenesis

Abstract rad6 mutants of Saccharomyces cerevisiae are defective in the repair of damaged DNA, DNA damage induced mutagenesis, and sporulation. In order to identify genes that can substitute for RAD6 function, we have isolated genomic suppressors of the UV sensitivity of rad6 deletion (rad6 delta) mutations and show that they also suppress the gamma-ray sensitivity but not the UV mutagenesis or sporulation defects of rad6. The suppressors show semidominance for suppression of UV sensitivity and dominance for suppression of gamma-ray sensitivity. The six suppressor mutations we isolated are all alleles of the same locus and are also allelic to a previously described suppressor of the rad6-1 nonsense mutation, SRS2. We show that suppression of rad6 delta is dependent on the RAD52 recombinational repair pathway since suppression is not observed in the rad6 delta SRS2 strain containing an additional mutation in either the RAD51, RAD52, RAD54, RAD55 or RAD57 genes. Possible mechanisms by which SRS2 may channel unrepaired DNA lesions into the RAD52 DNA repair pathway are discussed.

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The 45- and 104-kDa forms of phosphatidate phosphatase from Saccharomyces cerevisiae are regulated differentially by phosphorylation via cAMP-dependent protein kinase.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)37145-5 ◽

1992 ◽

Vol 267 (25) ◽

pp. 18013-18020

Author(s):

J.J. Quinlan ◽

J.T. Nickels ◽

W.I. Wu ◽

Y.P. Lin ◽

J.R. Broach ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Protein Kinase ◽

Phosphatidate Phosphatase ◽

Dependent Protein Kinase ◽

Camp Dependent Protein Kinase ◽

Dependent Protein

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The Schizosaccharomyces pombe cho1+ Gene Encodes a Phospholipid Methyltransferase

Genetics ◽

10.1093/genetics/150.2.553 ◽

1998 ◽

Vol 150 (2) ◽

pp. 553-562

Author(s):

Margaret I Kanipes ◽

John E Hill ◽

Susan A Henry

Keyword(s):

Saccharomyces Cerevisiae ◽

Sequence Analysis ◽

Schizosaccharomyces Pombe ◽

Gene Disruption ◽

Structure And Function ◽

Biosynthetic Enzyme ◽

Gene Encoding ◽

Complementation Groups ◽

Eukaryotic Organisms ◽

And Function

Abstract The isolation of mutants of Schizosaccharomyces pombe defective in the synthesis of phosphatidylcholine via the methylation of phosphatidylethanolamine is reported. These mutants are choline auxotrophs and fall into two unlinked complementation groups, cho1 and cho2. We also report the analysis of the cho1+ gene, the first structural gene encoding a phospholipid biosynthetic enzyme from S. pombe to be cloned and characterized. The cho1+ gene disruption mutant (cho1Δ) is viable if choline is supplied and resembles the cho1 mutants isolated after mutagenesis. Sequence analysis of the cho1+ gene indicates that it encodes a protein closely related to phospholipid methyltransferases from Saccharomyces cerevisiae and rat. Phospholipid methyltransferases encoded by a rat liver cDNA and the S. cerevisiae OPI3 gene are both able to complement the choline auxotrophy of the S. pombe cho1 mutants. These results suggest that both the structure and function of the phospholipid N-methyltransferases are broadly conserved among eukaryotic organisms.

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