scholarly journals The yeast SRM1 protein and human RCC1 protein share analogous functions.

1991 ◽  
Vol 2 (10) ◽  
pp. 781-792 ◽  
Author(s):  
K L Clark ◽  
M Ohtsubo ◽  
T Nishimoto ◽  
M Goebl ◽  
G F Sprague
Keyword(s):  
Null Allele ◽  
Nuclear Protein ◽  
Sequence Similarity ◽  
Signal Transduction Pathway ◽  
Amino Acid Sequence Similarity ◽  
Recessive Mutation ◽  
Temperature Sensitive ◽  
Pheromone Response Pathway ◽  
Mammalian Protein

The Saccharomyces cerevisiae protein SRM1 and the mammalian protein RCC1 have amino acid sequence similarity throughout their lengths. SRM1 was defined by a recessive mutation in yeast that both activates the signal transduction pathway required for mating and leads to arrest in the G1 phase of the cell cycle. RCC1 was defined by a recessive mutation in hamster cells that causes premature chromosome condensation and other characteristics of entry into mitosis. Despite the seemingly different roles implied by these phenotypes, we suggest that RCC1 and SRM1 proteins have similar functions. In particular, we find that RCC1 can complement the temperature-sensitive growth phenotype of two independent srm1 mutations and also complements, at least partially, phenotypes associated with activation of the pheromone response pathway, such as transcription induction of FUS1. However, RCC1 fails to complement an srm1 null allele. Further characterization of the srm1 mutant phenotype reveals a defect in plasmid and chromosome stability, suggesting that the mutants have a defect in DNA replication, mitosis, or their coordination. Finally, like RCC1, SRM1 is a nuclear protein. Together, these data imply that SRM1 and RCC1 have a common role in their respective organisms.

scholarly journals The yeast MOT2 gene encodes a putative zinc finger protein that serves as a global negative regulator affecting expression of several categories of genes, including mating-pheromone-responsive genes.

1994 ◽  
Vol 14 (5) ◽  
pp. 3150-3157 ◽  
Author(s):  
K Irie ◽  
K Yamaguchi ◽  
K Kawase ◽  
K Matsumoto
Keyword(s):  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Signal Transduction Pathway ◽  
Negative Regulator ◽  
Growth Defect ◽  
Recessive Mutation ◽  
Temperature Sensitive ◽  
Pheromone Response Pathway ◽  
Finger Protein ◽  
Putative Zinc Finger

The STE4 gene encodes the beta subunit of a heterotrimeric G protein that is an essential component of the pheromone signal transduction pathway. To identify downstream component(s) of Ste4, we sought pseudo-revertants that restored mating competence to ste4 mutants. The suppressor mot2 was isolated as a recessive mutation that restored conjugational competence to a temperature-sensitive ste4 mutant and simultaneously conferred a temperature-sensitive growth phenotype. The MOT2 gene encodes a putative zinc finger protein, the deletion of which resulted in temperature-sensitive growth, increased expression of FUS1 in the absence of pheromones, and suppression of a deletion of the alpha-factor receptor. On the other hand, sterility resulting from deletion of STE4 was not suppressed by the mot2 deletion. These phenotypes are similar to those associated with temperature-sensitive mutations in CDC36 and CDC39, which are proposed to encode general negative regulators of transcription rather than factors involved in the pheromone response pathway. Deletion of MOT2 also caused increased transcription of unrelated genes such as GAL7 and PHO84. Overexpression of MOT2 suppresses the growth defect of temperature-sensitive mutations in CDC36 and CDC39. These observations suggest that Mot2 functions as a general negative regulator of transcription in the same processes as Cdc36 and Cdc39.

The yeast MOT2 gene encodes a putative zinc finger protein that serves as a global negative regulator affecting expression of several categories of genes, including mating-pheromone-responsive genes

1994 ◽  
Vol 14 (5) ◽  
pp. 3150-3157
Author(s):  
K Irie ◽  
K Yamaguchi ◽  
K Kawase ◽  
K Matsumoto
Keyword(s):  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Signal Transduction Pathway ◽  
Negative Regulator ◽  
Growth Defect ◽  
Recessive Mutation ◽  
Temperature Sensitive ◽  
Pheromone Response Pathway ◽  
Finger Protein ◽  
Putative Zinc Finger

The STE4 gene encodes the beta subunit of a heterotrimeric G protein that is an essential component of the pheromone signal transduction pathway. To identify downstream component(s) of Ste4, we sought pseudo-revertants that restored mating competence to ste4 mutants. The suppressor mot2 was isolated as a recessive mutation that restored conjugational competence to a temperature-sensitive ste4 mutant and simultaneously conferred a temperature-sensitive growth phenotype. The MOT2 gene encodes a putative zinc finger protein, the deletion of which resulted in temperature-sensitive growth, increased expression of FUS1 in the absence of pheromones, and suppression of a deletion of the alpha-factor receptor. On the other hand, sterility resulting from deletion of STE4 was not suppressed by the mot2 deletion. These phenotypes are similar to those associated with temperature-sensitive mutations in CDC36 and CDC39, which are proposed to encode general negative regulators of transcription rather than factors involved in the pheromone response pathway. Deletion of MOT2 also caused increased transcription of unrelated genes such as GAL7 and PHO84. Overexpression of MOT2 suppresses the growth defect of temperature-sensitive mutations in CDC36 and CDC39. These observations suggest that Mot2 functions as a general negative regulator of transcription in the same processes as Cdc36 and Cdc39.

scholarly journals Characterization of a U.S. Isolate of Beet black scorch virus

2007 ◽  
Vol 97 (10) ◽  
pp. 1245-1254 ◽  
Author(s):  
John J. Weiland ◽  
David Van Winkle ◽  
Michael C. Edwards ◽  
Rebecca L. Larson ◽  
Weilin L. Shelver ◽  
...  
Keyword(s):  
Coat Protein ◽  
Protein Gene ◽  
Sequence Similarity ◽  
Systemic Infection ◽  
Amino Acid Sequence Similarity ◽  
Adenosine Nucleotides ◽  
Tetragonia Expansa ◽  
Extension Analysis ◽  
Beet Black Scorch Virus

The first reported U.S. isolate of Beet black scorch necrovirus (BBSV) was obtained and characterized. Host range of the virus for localized and occasionally systemic infection included the Chenopodiaceae and Tetragonia expansa; Nicotiana benthamiana supported symptomless systemic infection by the virus. The complete nucleotide sequence of the genomic RNA of the virus, designated BBSV-Co, exhibits 93% similarity to the genome of the ‘Ningxia’ isolate of BBSV from China. Amino acid sequence similarity in predicted genes ranged from 95% in the p4 gene to 97% in the p82 and coat protein genes. A potential additional gene exists within the U.S. isolate of BBSV that is absent from Chinese isolates of BBSV due to nucleotide differences between these isolates within the coat protein gene. Coat protein analysis by isoelectric focusing and by mass spectroscopy indicated the presence of phosphorylated residues. Using primer extension analysis of the 5′ end of the genome and site-directed mutants of genomic clones of BBSV-Co from which infectious RNA was produced, the native 5′ end of the BBSV-Co genome was determined to be 5′-GAAACCTAACC…3′, lacking the two terminal adenosine nucleotides in the published sequences of BBSV from China.

scholarly journals Characterization of the maize Mutator transposable element MURA transposase as a DNA-binding protein.

1997 ◽  
Vol 17 (9) ◽  
pp. 5165-5175 ◽  
Author(s):  
M I Benito ◽  
V Walbot
Keyword(s):  
Dna Binding ◽  
Transposable Element ◽  
Binding Protein ◽  
Sequence Similarity ◽  
Functional Characterization ◽  
Dna Binding Protein ◽  
Amino Acid Sequence Similarity ◽  
Mobility Shift ◽  
Gel Mobility Shift

The autonomous MuDR element of the Mutator (Mu) transposable element family of maize encodes at least two proteins, MURA and MURB. Based on amino acid sequence similarity, previous studies have reported that MURA is likely to be a transposase. The functional characterization of MURA has been hindered by the instability of its cDNA, mudrA, in Escherichia coli. In this study, we report the first successful stabilization and expression of MURA in Saccharomyces cerevisiae. Gel mobility shift assays demonstrate that MURA is a DNA-binding protein that specifically binds to sequences within the highly conserved Mu element terminal inverted repeats (TIRs). DNase I and 1,10-phenanthroline-copper footprinting of MURA-Mu1 TIR complexes indicate that MURA binds to a conserved approximately 32-bp region in the TIR of Mu1. In addition, MURA can bind to the same region in the TIRs of all tested actively transposing Mu elements but binds poorly to the diverged Mu TIRs of inactive elements. Previous studies have reported a correlation between Mu transposon inactivation and methylation of the Mu element TIRs. Gel mobility shift assays demonstrate that MURA can interact differentially with unmethylated, hemimethylated, and homomethylated TIR substrates. The significance of MURA's interaction with the TIRs of Mu elements is discussed in the context of what is known about the regulation and mechanisms of Mutator activities in maize.

scholarly journals Suppression of a sec63 mutation identifies a novel component of the yeast endoplasmic reticulum translocation apparatus.

1993 ◽  
Vol 4 (9) ◽  
pp. 919-930 ◽  
Author(s):  
T Kurihara ◽  
P Silver
Keyword(s):  
Endoplasmic Reticulum ◽  
Null Allele ◽  
Nuclear Protein ◽  
Protein Translocation ◽  
Protein Localization ◽  
Temperature Sensitive ◽  
Membrane Glycoprotein ◽  
N Terminus ◽  
Allele Specific ◽  
Synthetically Lethal

Mutations in the SEC63 gene are associated with defects in protein translocation into the endoplasmic reticulum (ER) as well as in nuclear protein localization in Saccharomyces cerevisiae. To identify proteins that might interact and/or function with SEC63p, we cloned a high copy suppressor (HSS1) of the temperature-sensitive lethal phenotype of the sec63-101 mutant. HSS1 is an allele-specific sec63 suppressor that encodes an integral ER membrane glycoprotein of 206 amino acids with the N-terminus in the ER lumen and C-terminal region in the cytoplasm. Haploid strains disrupted for HSS1 are temperature-sensitive for growth and accumulate precursor forms of Kar2p and invertase. The HSS1 null allele is synthetically lethal in combination with mutations affecting ER translocation. We propose that HSS1p is important for ER translocation and interacts with previously identified components of the yeast translocation apparatus. HSS1 is identical to SEC66, which encodes a glycoprotein complexed with SEC62p and SEC63p.

scholarly journals Crystal and solution structures reveal oligomerization of individual capsid homology domains of Drosophila Arc

2020 ◽  
Author(s):  
Erik I. Hallin ◽  
Sigurbjörn Markússon ◽  
Lev Böttger ◽  
Andrew E. Torda ◽  
Clive R. Bramham ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Brain Function ◽  
Sequence Similarity ◽  
Solution Structures ◽  
Terminal Domain ◽  
Large N ◽  
Structural Homologues ◽  
Mammalian Protein

AbstractSynaptic plasticity is vital for brain function and memory formation. One of the key proteins in long-term synaptic plasticity and memory is the activity-regulated cytoskeleton-associated protein (Arc). Mammalian Arc forms virus-like capsid-like structures in a process requiring the N-terminal domain and contains two C-terminal lobes that are structural homologues to retroviral capsids. Drosophila has two isoforms of Arc, dArc1 and dArc2, with low sequence similarity to mammalian Arc, but lacking the mammalian Arc N-terminal domain. Both dArc isoforms have a capsid homology domain consisting of N- and C-terminal lobes. We carried out structural characterization of the four individual dArc lobe domains. As opposed to the corresponding mammalian Arc lobe domains, which are monomeric, the dArc lobes were all oligomeric in solution, indicating a strong propensity for homophilic interactions. The N-lobe from dArc2 formed a domain-swapped dimer in the crystal structure, resulting in a novel dimer interaction that could be relevant for capsid assembly or other dArc functions. This domain-swapped structure resembles the dimeric protein C of flavivirus capsids, as well as the structure of histones dimers, domain-swapped transcription factors, and membrane-interacting BAK domains. The strong oligomerization properties of the isolated dArc lobe domains explain the ability of dArc to form capsids in the absence of any large N-terminal domain, in contrast to the mammalian protein.

scholarly journals Yeast pheromone response pathway: characterization of a suppressor that restores mating to receptorless mutants.

1989 ◽  
Vol 9 (6) ◽  
pp. 2682-2694 ◽  
Author(s):  
K L Clark ◽  
G F Sprague
Keyword(s):  
Essential Gene ◽  
Receptor Gene ◽  
Cell Types ◽  
Recessive Mutation ◽  
Temperature Sensitive ◽  
Haploid Cell ◽  
Nonpermissive Temperature ◽  
Pheromone Response ◽  
Pheromone Response Pathway ◽  
Alpha Factor

Saccharomyces cerevisiae haploid cells, alpha and a, mate after being appropriately stimulated by the pheromone secreted by the opposite cell type (a-factor and alpha-factor, respectively). The binding of a pheromone to its receptor is a signal that initiates a series of intracellular changes that lead to the specific physiological alterations required for mating. To identify components of the signal transduction pathway, we sought pseudorevertants that restored mating competence to receptor mutants (MAT alpha ste3::LEU2). The suppressor srm1-1 was isolated as a recessive mutation that conferred temperature-sensitive growth to all strains and mating ability to MAT alpha ste3::LEU2 strains at the nonpermissive temperature. In addition, when srm1-1 mutants were shifted to the nonpermissive temperature, they exhibited two phenotypes characteristic of pheromone response, induction of FUS1 transcription and accumulation of cells in the G1 phase of the cell cycle. The srm1-1 mutation also suppressed a deletion of the alpha-factor-receptor gene in a cells. Together, these phenotypes suggest that the wild-type SRM1 product is a component of the pheromone response pathway. Deletion of STE4 or STE5, which are required in both haploid cell types for mating and response to pheromone, was not suppressed by srm1-1, suggesting that the SRM1 product may function before the STE4 and STE5 products. SRM1 is an essential gene and is expressed in both haploid cell types as well as in the product of their mating, a/alpha diploids. Homozygous srm1-1 a/alpha diploids were temperature sensitive although they did not arrest in G1. Thus, the SRM1 product may also have a role in the vegetative life cycle of cells.

scholarly journals Characterization of the Isophthalate Degradation Genes of Comamonas sp. Strain E6

2009 ◽  
Vol 76 (2) ◽  
pp. 519-527 ◽  
Author(s):  
Yuki Fukuhara ◽  
Keisuke Inakazu ◽  
Norimichi Kodama ◽  
Naofumi Kamimura ◽  
Daisuke Kasai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Sequence Similarity ◽  
Transcriptional Regulator ◽  
Complete Loss ◽  
Transcriptional Unit ◽  
Energy Sources ◽  
Amino Acid Sequence Similarity ◽  
Two Component

ABSTRACT The isophthalate (IPA) degradation gene cluster (iphACBDR) responsible for the conversion of IPA into protocatechuate (PCA) was isolated from Comamonas sp. strain E6, which utilizes phthalate isomers as sole carbon and energy sources via the PCA 4,5-cleavage pathway. Based on amino acid sequence similarity, the iphA, iphC, iphB, iphD, and iphR genes were predicted to code for an oxygenase component of IPA dioxygenase (IPADO), a periplasmic IPA binding receptor, a 1,2-dihydroxy-3,5-cyclohexadiene-1,5-dicarboxylate (1,5-DCD) dehydrogenase, a reductase component of IPADO, and an IclR-type transcriptional regulator, respectively. The iphACBDR genes constitute a single transcriptional unit, and transcription of the iph catabolic operon was induced during growth of E6 on IPA. The iphA, iphD, and iphB genes were expressed in Escherichia coli. Crude IphA and IphD converted IPA in the presence of NADPH into a product which was transformed to PCA by IphB. These results suggested that IPADO is a two-component dioxygenase that consists of a terminal oxygenase component (IphA) and a reductase component (IphD) and that iphB encodes the 1,5-DCD dehydrogenase. Disruption of iphA and iphB resulted in complete loss of growth of E6 on IPA. Inactivation of iphD significantly affected growth on IPA, and the iphC mutant did not grow on IPA at neutral pH. These results indicated that the iphACBD genes are essential for the catabolism of IPA in E6. Disruption of iphR resulted in faster growth of E6 on IPA, suggesting that iphR encodes a repressor for the iph catabolic operon. Promoter analysis of the operon supported this notion.

Yeast pheromone response pathway: characterization of a suppressor that restores mating to receptorless mutants

1989 ◽  
Vol 9 (6) ◽  
pp. 2682-2694
Author(s):  
K L Clark ◽  
G F Sprague
Keyword(s):  
Essential Gene ◽  
Receptor Gene ◽  
Cell Types ◽  
Recessive Mutation ◽  
Temperature Sensitive ◽  
Haploid Cell ◽  
Nonpermissive Temperature ◽  
Pheromone Response ◽  
Pheromone Response Pathway ◽  
Alpha Factor

Saccharomyces cerevisiae haploid cells, alpha and a, mate after being appropriately stimulated by the pheromone secreted by the opposite cell type (a-factor and alpha-factor, respectively). The binding of a pheromone to its receptor is a signal that initiates a series of intracellular changes that lead to the specific physiological alterations required for mating. To identify components of the signal transduction pathway, we sought pseudorevertants that restored mating competence to receptor mutants (MAT alpha ste3::LEU2). The suppressor srm1-1 was isolated as a recessive mutation that conferred temperature-sensitive growth to all strains and mating ability to MAT alpha ste3::LEU2 strains at the nonpermissive temperature. In addition, when srm1-1 mutants were shifted to the nonpermissive temperature, they exhibited two phenotypes characteristic of pheromone response, induction of FUS1 transcription and accumulation of cells in the G1 phase of the cell cycle. The srm1-1 mutation also suppressed a deletion of the alpha-factor-receptor gene in a cells. Together, these phenotypes suggest that the wild-type SRM1 product is a component of the pheromone response pathway. Deletion of STE4 or STE5, which are required in both haploid cell types for mating and response to pheromone, was not suppressed by srm1-1, suggesting that the SRM1 product may function before the STE4 and STE5 products. SRM1 is an essential gene and is expressed in both haploid cell types as well as in the product of their mating, a/alpha diploids. Homozygous srm1-1 a/alpha diploids were temperature sensitive although they did not arrest in G1. Thus, the SRM1 product may also have a role in the vegetative life cycle of cells.

scholarly journals Characterization of the Terephthalate Degradation Genes of Comamonas sp. Strain E6

2006 ◽  
Vol 72 (3) ◽  
pp. 1825-1832 ◽  
Author(s):  
Mikio Sasoh ◽  
Eiji Masai ◽  
Satoko Ishibashi ◽  
Hirofumi Hara ◽  
Naofumi Kamimura ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Large Subunit ◽  
Transcriptional Regulator ◽  
Gene Clusters ◽  
Small Subunit ◽  
Amino Acid Sequence Similarity ◽  
Comamonas Testosteroni ◽  
Cell Extracts ◽  
Two Component

ABSTRACT We isolated Comamonas sp. strain E6, which utilizes terephthalate (TPA) as the sole carbon and energy source via the protocatechuate (PCA) 4,5-cleavage pathway. Two almost identical TPA degradation gene clusters, tphR I C I A2 I A3 I B I A1 I and tphR II C II A2 II A3 II B II A1 II, were isolated from this strain. Based on amino acid sequence similarity, the genes tphR, tphC, tphA2, tphA3, tphB, and tphA1 were predicted to code, respectively, for an IclR-type transcriptional regulator, a periplasmic TPA binding receptor, the large subunit of the oxygenase component of TPA 1,2-dioxygenase (TPADO), the small subunit of the oxygenase component of TPADO, a 1,2-dihydroxy-3,5-cyclohexadiene-1,4-dicarboxylate (DCD) dehydrogenase, and a reductase component of TPADO. The growth of E6 on TPA was not affected by disruption of either tphA2 I or tphA2 II singly; however, the tphA2 I tphA2 II double mutant no longer grew on TPA, suggesting that both TPADO genes are involved in TPA degradation. Introduction of a plasmid carrying tphR II C II A2 II A3 II B II A1 II conferred the TPA utilization phenotype on Comamonas testosteroni IAM 1152, which is able to grow on PCA but not on TPA. Disruption of either tphR II or tphC II on this plasmid resulted in the loss of the growth of IAM 1152 on TPA, suggesting that these genes are essential to convert TPA to PCA in E6. The genes tphA1 II, tphA2 II, tphA3 II, and tphB II were expressed in Escherichia coli, and the resultant cell extracts containing TphA1II, TphA2II, and TphA3II converted TPA in the presence of NADPH into a product which was transformed to PCA by TphBII. On the basis of these results, TPADO was strongly suggested to be a two-component dioxygenase which consists of the terminal oxygenase component (TphA2 and TphA3) and the reductase (TphA1), and tphB codes for the DCD dehydrogenase.

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