scholarly journals YHR150w and YDR479c encode peroxisomal integral membrane proteins involved in the regulation of peroxisome number, size, and distribution in Saccharomyces cerevisiae

2003 ◽  
Vol 161 (2) ◽  
pp. 321-332 ◽  
Author(s):  
Franco J. Vizeacoumar ◽  
Juan C. Torres-Guzman ◽  
Yuen Yi C. Tam ◽  
John D. Aitchison ◽  
Richard A. Rachubinski
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sequence Similarity ◽  
Buoyant Density ◽  
Integral Membrane Proteins ◽  
Hypothetical Proteins ◽  
Wild Type ◽  
Peroxisomal Membrane ◽  
High Sequence Similarity ◽  
Wild Type Phenotype ◽  
Yeast Yarrowia Lipolytica

The peroxin Pex24p of the yeast Yarrowia lipolytica exhibits high sequence similarity to two hypothetical proteins, Yhr150p and Ydr479p, encoded by the Saccharomyces cerevisiae genome. Like YlPex24p, both Yhr150p and Ydr479p have been shown to be integral to the peroxisomal membrane, but unlike YlPex24p, their levels of synthesis are not increased upon a shift of cells from glucose- to oleic acid–containing medium. Peroxisomes of cells deleted for either or both of the YHR150w and YDR479c genes are increased in number, exhibit extensive clustering, are smaller in area than peroxisomes of wild-type cells, and often exhibit membrane thickening between adjacent peroxisomes in a cluster. Peroxisomes isolated from cells deleted for both genes have a decreased buoyant density compared with peroxisomes isolated from wild-type cells and still exhibit clustering and peroxisomal membrane thickening. Overexpression of the genes PEX25 or VPS1, but not the gene PEX11, restored the wild-type phenotype to cells deleted for one or both of the YHR150w and YDR479c genes. Together, our data suggest a role for Yhr150p and Ydr479p, together with Pex25p and Vps1p, in regulating peroxisome number, size, and distribution in S. cerevisiae. Because of their role in peroxisome dynamics, YHR150w and YDR479c have been designated as PEX28 and PEX29, respectively, and their encoded peroxins as Pex28p and Pex29p.

scholarly journals Pex30p, Pex31p, and Pex32p Form a Family of Peroxisomal Integral Membrane Proteins Regulating Peroxisome Size and Number in Saccharomyces cerevisiae

2004 ◽  
Vol 15 (2) ◽  
pp. 665-677 ◽  
Author(s):  
Franco J. Vizeacoumar ◽  
Juan C. Torres-Guzman ◽  
David Bouard ◽  
John D. Aitchison ◽  
Richard A. Rachubinski
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oleic Acid ◽  
Yarrowia Lipolytica ◽  
Sequence Similarity ◽  
Integral Membrane Proteins ◽  
Peroxisome Proliferation ◽  
Hypothetical Proteins ◽  
Peroxisomal Membrane ◽  
High Sequence Similarity ◽  
Yeast Yarrowia Lipolytica

The peroxin Pex23p of the yeast Yarrowia lipolytica exhibits high sequence similarity to the hypothetical proteins Ylr324p, Ygr004p, and Ybr168p encoded by the Saccharomyces cerevisiae genome. Ylr324p, Ygr004p, and Ybr168p are integral to the peroxisomal membrane and act to control peroxisome number and size. Synthesis of Ylr324p and Ybr168p, but not of Ygr004p, is induced during incubation of cells in oleic acid-containing medium, the metabolism of which requires intact peroxisomes. Cells deleted for YLR324w exhibit increased numbers of peroxisomes, whereas cells deleted for YGR004w or YBR168w exhibit enlarged peroxisomes. Ylr324p and Ybr168p cannot functionally substitute for one another or for Ygr004p, whereas Ygr004p shows partial functional redundancy with Ylr324p and Ybr168p. Ylr324p, Ygr004p, and Ybr168p interact within themselves and with Pex28p and Pex29p, which have been shown also to regulate peroxisome size and number. Systematic deletion of genes demonstrated that PEX28 and PEX29 function upstream of YLR324w, YGR004w, and YBR168w in the regulation of peroxisome proliferation. Our data suggest a role for Ylr324p, Ygr004p, and Ybr168p—now designated Pex30p, Pex31p, and Pex32p, respectively—together with Pex28p and Pex29p in controlling peroxisome size and proliferation in Saccharomyces cerevisiae.

scholarly journals Mutants of theYarrowia lipolytica PEX23Gene Encoding an Integral Peroxisomal Membrane Peroxin Mislocalize Matrix Proteins and Accumulate Vesicles Containing Peroxisomal Matrix and Membrane Proteins

2000 ◽  
Vol 11 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Trevor W. Brown ◽  
Vladimir I. Titorenko ◽  
Richard A. Rachubinski
Keyword(s):  
Membrane Proteins ◽  
Sequence Similarity ◽  
Integral Membrane Protein ◽  
Functional Complementation ◽  
Matrix Proteins ◽  
Hypothetical Proteins ◽  
Peroxisomal Membrane ◽  
High Sequence Similarity ◽  
Low Levels ◽  
Yeast Yarrowia Lipolytica

pex mutants are defective in peroxisome assembly. The mutant strain pex23-1 of the yeast Yarrowia lipolytica lacks morphologically recognizable peroxisomes and mislocalizes all peroxisomal matrix proteins investigated preferentially to the cytosol. pex23 strains accumulate vesicular structures containing both peroxisomal matrix and membrane proteins. The PEX23 gene was isolated by functional complementation of the pex23-1 strain and encodes a protein, Pex23p, of 418 amino acids (47,588 Da). Pex23p exhibits high sequence similarity to two hypothetical proteins of the yeastSaccharomyces cerevisiae. Pex23p is an integral membrane protein of peroxisomes that is completely, or nearly completely, sequestered from the cytosol. Pex23p is detected at low levels in cells grown in medium containing glucose, and its levels are significantly increased by growth in medium containing oleic acid, the metabolism of which requires intact peroxisomes.

scholarly journals Pex11-related Proteins in Peroxisome Dynamics: A Role for the Novel Peroxin Pex27p in Controlling Peroxisome Size and Number in Saccharomyces cerevisiae

2003 ◽  
Vol 14 (10) ◽  
pp. 4089-4102 ◽  
Author(s):  
Yuen Yi C. Tam ◽  
Juan C. Torres-Guzman ◽  
Franco J. Vizeacoumar ◽  
Jennifer J. Smith ◽  
Marcello Marelli ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sequence Similarity ◽  
Transcriptome Profiling ◽  
The Novel ◽  
Yeast Two Hybrid ◽  
Peroxisomal Membrane ◽  
High Sequence Similarity ◽  
Reading Frame ◽  
Related Proteins ◽  
Two Hybrid

Transcriptome profiling identified the gene PEX25 encoding Pex25p, a peroxisomal membrane peroxin required for the regulation of peroxisome size and maintenance in Saccharomyces cerevisiae. Pex25p is related to a protein of unknown function encoded by the open reading frame, YOR193w, of the S. cerevisiae genome. Yor193p is a peripheral peroxisomal membrane protein that exhibits high sequence similarity not only to Pex25p but also to the peroxisomal membrane peroxin Pex11p. Unlike Pex25p and Pex11p, Yor193p is constitutively expressed in wild-type cells grown in oleic acid-containing medium, the metabolism of which requires intact peroxisomes. Cells deleted for the YOR193w gene show a few enlarged peroxisomes. Peroxisomes are greatly enlarged in cells harboring double deletions of the YOR193w and PEX25 genes, the YOR193w and PEX11 genes, and the PEX25 and PEX11 genes. Yeast two-hybrid analyses showed that Yor193p interacts with Pex25p and itself, Pex25p interacts with Yor193p and itself, and Pex11p interacts only with itself. Overexpression of YOR193w, PEX25, or PEX11 led to peroxisome proliferation and the formation of small peroxisomes. Our data suggest a role for Yor193p, renamed Pex27p, in controlling peroxisome size and number in S. cerevisiae.

scholarly journals A Nuclear Import Pathway for a Protein Involved in tRNA Maturation

1997 ◽  
Vol 139 (7) ◽  
pp. 1655-1661 ◽  
Author(s):  
Jonathan S. Rosenblum ◽  
Lucy F. Pemberton ◽  
Günter Blobel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Import ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Sequence Similarity ◽  
Wild Type ◽  
Major Pathway ◽  
Trna Processing ◽  
Transport Factors ◽  
Limited Sequence

A limited number of transport factors, or karyopherins, ferry particular substrates between the cytoplasm and nucleoplasm. We identified the Saccharomyces cerevisiae gene YDR395w/SXM1 as a potential karyopherin on the basis of limited sequence similarity to known karyopherins. From yeast cytosol, we isolated Sxm1p in complex with several potential import substrates. These substrates included Lhp1p, the yeast homologue of the human autoantigen La that has recently been shown to facilitate maturation of pre-tRNA, and three distinct ribosomal proteins, Rpl16p, Rpl25p, and Rpl34p. Further, we demonstrate that Lhp1p is specifically imported by Sxm1p. In the absence of Sxm1p, Lhp1p was mislocalized to the cytoplasm. Sxm1p and Lhp1p represent the karyopherin and a cognate substrate of a unique nuclear import pathway, one that operates upstream of a major pathway of pre-tRNA maturation, which itself is upstream of tRNA export in wild-type cells. In addition, through its association with ribosomal proteins, Sxm1p may have a role in coordinating ribosome biogenesis with tRNA processing.

scholarly journals Giant peroxisomes in oleic acid-induced Saccharomyces cerevisiae lacking the peroxisomal membrane protein Pmp27p.

1995 ◽  
Vol 128 (4) ◽  
pp. 509-523 ◽  
Author(s):  
R Erdmann ◽  
G Blobel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oleic Acid ◽  
Growth Defect ◽  
Wild Type ◽  
Peroxisomal Membrane ◽  
Daughter Cells ◽  
Sds Page ◽  
Multiple Buds ◽  
Media Form ◽  
Tubular Membranes

We have purified peroxisomal membranes from Saccharomyces cerevisiae after induction of peroxisomes in oleic acid-containing media. About 30 distinct proteins could be discerned among the HPLC- and SDS-PAGE-separated proteins of the high salt-extracted peroxisomal membranes. The most abundant of these, Pmp27p, was purified and the corresponding gene PMP27 was cloned and sequenced. Its primary structure is 32% identical to PMP31 and PMP32 of the yeast Candida biodinii (Moreno, M., R. Lark, K. L. Campbell, and M. J. Goodman. 1994. Yeast. 10:1447-1457). Immunoelectron microscopic localization of Pmp27p showed labeling of the peroxisomal membrane, but also of matrix-less and matrix containing tubular membranes nearby. Electronmicroscopical data suggest that some of these tubular extensions might interconnect peroxisomes to form a peroxisomal reticulum. Cells with a disrupted PMP27 gene (delta pmp27) still grew well on glucose or ethanol, but they failed to grow on oleate although peroxisomes were still induced by transfer to oleate-containing media. The induced peroxisomes of delta pmp27 cells were fewer but considerably larger than those of wild-type cells, suggesting that Pmp27p may be involved in parceling of peroxisomes into regular quanta. delta pmp27 cells cultured in oleate-containing media form multiple buds, of which virtually all are peroxisome deficient. The growth defect of delta pmp27 cells on oleic acid appears to result from the inability to segregate the giant peroxisomes to daughter cells.

scholarly journals Identification and Functional Characterization of the Novel Edwardsiella tarda Effector EseJ

2015 ◽  
Vol 83 (4) ◽  
pp. 1650-1660 ◽  
Author(s):  
Hai-Xia Xie ◽  
Jin-Fang Lu ◽  
Ying Zhou ◽  
Jia Yi ◽  
Xiu-Jun Yu ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Bacterial Adhesion ◽  
Sequence Similarity ◽  
Functional Characterization ◽  
Lethal Dose ◽  
Edwardsiella Tarda ◽  
Bacterial Cells ◽  
Wild Type ◽  
High Sequence Similarity ◽  
Content Type

Edwardsiella tardais a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and gastro- and extraintestinal infections in humans. The type III secretion system (T3SS) ofE. tardahas been identified as a key virulence factor that contributes to pathogenesis in fish. However, little is known about the associated effectors translocated by this T3SS. In this study, by comparing the profile of secreted proteins of the wild-type PPD130/91 and its T3SS ATPase ΔesaNmutant, we identified a new effector by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. This effector consists of 1,359 amino acids, sharing high sequence similarity with Orf29/30 ofE. tardastrain EIB202, and is renamed EseJ. The secretion and translocation of EseJ depend on the T3SS. A ΔeseJmutant strain adheres to epithelioma papillosum of carp (EPC) cells 3 to 5 times more extensively than the wild-type strain does. EseJ inhibits bacterial adhesion to EPC cells from within bacterial cells. Importantly, the ΔeseJmutant strain does not replicate efficiently in EPC cells and fails to replicate in J774A.1 macrophages. In infected J774A.1 macrophages, the ΔeseJmutant elicits higher production of reactive oxygen species than wild-typeE. tarda. The replication defect is consistent with the attenuation of the ΔeseJmutant in the blue gourami fish model: the 50% lethal dose (LD50) of the ΔeseJmutant is 2.34 times greater than that of the wild type, and the ΔeseJmutant is less competitive than the wild type in mixed infection. Thus, EseJ represents a novel effector that contributes to virulence by reducing bacterial adhesion to EPC cells and facilitating intracellular bacterial replication.

scholarly journals Prohibitin Family Members Interact Genetically with Mitochondrial Inheritance Components in Saccharomyces cerevisiae

1998 ◽  
Vol 18 (7) ◽  
pp. 4043-4052 ◽  
Author(s):  
Karen H. Berger ◽  
Michael P. Yaffe
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Outer Membrane ◽  
Integral Membrane Proteins ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Morphology ◽  
Mitochondrial Inheritance ◽  
Loss Of Function ◽  
Wild Type ◽  
Mitochondrial Inner Membrane ◽  
Synthetically Lethal

ABSTRACT Phb2p, a homolog of the tumor suppressor protein prohibitin, was identified in a genetic screen for suppressors of the loss of Mdm12p, a mitochondrial outer membrane protein required for normal mitochondrial morphology and inheritance in Saccharomyces cerevisiae. Phb2p and its homolog, prohibitin (Phb1p), were localized to the mitochondrial inner membrane and characterized as integral membrane proteins which depend on each other for their stability. In otherwise wild-type genetic backgrounds, null mutations in PHB1 andPHB2 did not confer any obvious phenotypes. However, loss of function of either PHB1 or PHB2 in cells with mitochondrial DNA deleted led to altered mitochondrial morphology, and phb1 or phb2 mutations were synthetically lethal when combined with a mutation in any of three mitochondrial inheritance components of the mitochondrial outer membrane, Mdm12p, Mdm10p, and Mmm1p. These results provide the first evidence of a role for prohibitin in mitochondrial inheritance and in the regulation of mitochondrial morphology.

scholarly journals Inheritance of seedlessness and the molecular characterization of the INO gene in Annonaceae

2023 ◽  
Vol 83 ◽  
Author(s):  
B. R. R. M. Nassau ◽  
P. S. C. Mascarenhas ◽  
A. G. Guimarães ◽  
F. M. Feitosa ◽  
H. M. Ferreira ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Type A ◽  
Molecular Techniques ◽  
Wild Type ◽  
Annona Squamosa ◽  
High Sequence Similarity ◽  
Breeding Programs ◽  
Complete Dominance ◽  
Young Leaves

Abstract The inheritance of the seedless fruit characteristic of Annona squamosa has not yet been explained. Molecular techniques may aid breeding programs, mainly in the assisted selection of the target gene. The INO gene may be related to seed development in these fruits. The objective of the present paper was to investigate the inheritance of seedlessness in the 'Brazilian seedless' sugar apple and INO gene conservation in Annona squamosa and Annona cherimola x Annona squamosa genotypes by assessing their homology with the INO database genes. The F1 generation was obtained by crossing the mutant 'Brazilian seedless' (male genitor) (P1) with the wild-type A. squamosa with seeds (M1 and M2, female genitors). The INO gene was studied in mutant and wild-type A. squamosa (P1, M1, M2 and M3) and in the Gefner atemoya (A. cherimola x A. squamosa) (M4) cultivar. The DNA was extracted from young leaves, and four sets of specific primers flanking the INO gene were amplified. The seedless characteristic was identified as stenospermatic in the fruits of parental P1, suggesting monogenic inheritance with complete dominance. High sequence similarity of the INO gene amplifications in the sugar apple accessions (M1, M2, M3) and the atemoya cultivar Gefner (M4) reinforces the hypothesis of their conservation.

scholarly journals Pmp27 promotes peroxisomal proliferation.

1995 ◽  
Vol 129 (2) ◽  
pp. 345-355 ◽  
Author(s):  
P A Marshall ◽  
Y I Krimkevich ◽  
R H Lark ◽  
J M Dyer ◽  
M Veenhuis ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Sequence Similarity ◽  
Carbon Sources ◽  
Weight Of Evidence ◽  
Candida Boidinii ◽  
Multicopy Plasmid ◽  
Wild Type ◽  
Beta Oxidation ◽  
Peroxisomal Membrane ◽  
A Cell

Peroxisomes perform many essential functions in eukaryotic cells. The weight of evidence indicates that these organelles divide by budding from preexisting peroxisomes. This process is not understood at the molecular level. Peroxisomal proliferation can be induced in Saccharomyces cerevisiae by oleate. This growth substrate is metabolized by peroxisomal enzymes. We have identified a protein, Pmp27, that promotes peroxisomal proliferation. This protein, previously termed Pmp24, was purified from peroxisomal membranes, and the corresponding gene, PMP27, was isolated and sequenced. Pmp27 shares sequence similarity with the Pmp30 family in Candida boidinii. Pmp27 is a hydrophobic peroxisomal membrane protein but it can be extracted by high pH, suggesting that it does not fully span the bilayer. Its expression is regulated by oleate. The function of Pmp27 was probed by observing the phenotype of strains in which the protein was eliminated by gene disruption or overproduced by expression from a multicopy plasmid. The strain containing the disruption (3B) was able to grow on all carbon sources tested, including oleate, although growth on oleate, glycerol, and acetate was slower than wild type. Strain 3B contained peroxisomes with all of the enzymes of beta-oxidation. However, in addition to the presence of a few modestly sized peroxisomes seen in a typical thin section of a cell growing on oleate-containing medium, cells of strain 3B also contained one or two very large peroxisomes. In contrast, cells in a strain in which Pmp27 was overexpressed contained an increased number of normal-sized peroxisomes. We suggest that Pmp27 promotes peroxisomal proliferation by participating in peroxisomal elongation or fission.

scholarly journals Tagging Morphogenetic Genes by Insertional Mutagenesis in the Yeast Yarrowia lipolytica

2001 ◽  
Vol 183 (10) ◽  
pp. 3098-3107 ◽  
Author(s):  
Mathias Richard ◽  
Raymundo Rosas Quijano ◽  
Samira Bezzate ◽  
Florence Bordon-Pallier ◽  
Claude Gaillardin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yarrowia Lipolytica ◽  
Cell Walls ◽  
Type Strain ◽  
Insertional Mutagenesis ◽  
Wild Type Strain ◽  
Wild Type ◽  
Calcofluor White ◽  
Hyphal Formation ◽  
Yeast Yarrowia Lipolytica

ABSTRACT The yeast Yarrowia lipolytica is distantly related to Saccharomyces cerevisiae, can be genetically modified, and can grow in both haploid and diploid states in either yeast, pseudomycelial, or mycelial forms, depending on environmental conditions. Previous results have indicated that the STEand RIM pathways, which mediate cellular switching in other dimorphic yeasts, are not required for Y. lipolytica morphogenesis. To identify the pathways involved in morphogenesis, we mutagenized a wild-type strain of Y. lipolytica with a Tn3 derivative. We isolated eight tagged mutants, entirely defective in hyphal formation, from a total of 40,000 mutants and identified seven genes homologous toS. cerevisiae CDC25, RAS2, BUD6, KEX2, GPI7, SNF5, andPPH21. We analyzed their abilities to invade agar and to form pseudomycelium or hyphae under inducing conditions and their sensitivity to temperature and to Calcofluor white. Chitin staining was used to detect defects in their cell walls. Our results indicate that a functional Ras-cyclic AMP pathway is required for the formation of hyphae in Y. lipolytica and that perturbations in the processing of extracellular, possibly parietal, proteins result in morphogenetic defects.

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