Suppressor analyses of temperature-sensitive cbp1 strains of Saccharomyces cerevisiae: the product of the nuclear gene SOC1 affects mitochondrial cytochrome b mRNA post-transcriptionally.

Genetics ◽  
1994 ◽  
Vol 138 (3) ◽  
pp. 565-575
Author(s):  
R R Staples ◽  
C L Dieckmann
Keyword(s):  
Cytochrome B ◽  
Nuclear Gene ◽  
State Level ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Mitochondrial Cytochrome ◽  
Mitochondrial Cytochrome B ◽  
Cytochrome B Mrna ◽  
Bypass Mechanism

Abstract The induction of mitochondrial function is dependent upon both nuclearly encoded and mitochondrially encoded gene products. To understand nuclear-mitochondrial interactions, we must first understand gene-specific interactions. The accumulation of mitochondrial cytochrome b (COB) RNA is dependent upon Cbp1p, encoded by the nuclear gene CBP1. Thus, respiration is dependent upon Cbp1p. In this study, suppressors of temperature-sensitive cbp1 (cbp1ts) strains were selected for restoration of respiratory capability at the restrictive temperature Ts+). One nuclearly encoded suppressor, extragenic to CBP1, is recessive with respect to the wild-type suppressor allele and is unlinked to other known genetic loci whose gene products are necessary for expression of COB mRNA. The suppressor, called soc1 for Suppressor of cbp1, suppresses several other cbp1ts alleles but does not operate via a bypass mechanism. Molecular analyses indicate that soc1 allows the steady-state level of COB mRNA to increase at high temperature but has little or no effect on the levels of COB pre-mRNA. These data have led us to propose that the product of the nuclear gene SOC1 is required for normal turnover of COB mRNA.

Ovarian mitochondrial cytochrome b mRNA levels increase with sexual maturity in freshwater eels (Anguilla spp.)

2003 ◽  
Vol 173 (1) ◽  
pp. 11-19 ◽  
Author(s):  
P. Lokman ◽  
Y. Kazeto ◽  
S. Ijiri ◽  
G. Young ◽  
T. Miura ◽  
...  
Keyword(s):  
Cytochrome B ◽  
Sexual Maturity ◽  
Mrna Levels ◽  
Mitochondrial Cytochrome ◽  
Mitochondrial Cytochrome B ◽  
Cytochrome B Mrna ◽  
Freshwater Eels

scholarly journals Premature 3'-end formation of CBP1 mRNA results in the downregulation of cytochrome b mRNA during the induction of respiration in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (8) ◽  
pp. 4199-4207 ◽  
Author(s):  
K A Sparks ◽  
S A Mayer ◽  
C L Dieckmann
Keyword(s):  
Mutant Strain ◽  
Cytochrome B ◽  
Nuclear Gene ◽  
State Level ◽  
Transcript Level ◽  
Unexpected Result ◽  
Coordinate Regulation ◽  
Growth Properties ◽  
Cytochrome B Mrna ◽  
Responsive Element

The yeast mitochondrial genome encodes only seven major components of the respiratory chain and ATP synthase; more than 200 other mitochondrial proteins are encoded by nuclear genes. Thus, assembly of functional mitochondria requires coordinate expression of nuclear and mitochondrial genes. One example of coordinate regulation is the stabilization of mitochondrial COB (cytochrome b) mRNA by Cbp1, the product of the nuclear gene CBP1 (cytochrome b processing). CBP1 produces two types of transcripts with different 3' ends: full-length 2.2-kb transcripts and 1.2-kb transcripts truncated within the coding sequence of Cbp1. Upon induction of respiration, the steady-state level of the long transcripts decreases while that of the short transcripts increases reciprocally, an unexpected result since the product of the long transcripts is required for COB mRNA stability and thus for respiration. Here we have tested the hypothesis that the short transcripts, or proteins translated from the short transcripts, are also required for respiration. A protein translated from the short transcripts was not detected by Western analysis, although polysome gradient fractions were shown to contain both long and short CBP1 transcripts. A mutant strain in which production of the short transcripts was abolished showed wild-type growth properties, indicating that the short transcripts are not required for respiration. Due to mutation of the carbon source-responsive element, the long transcript level in the mutant strain did not decrease during induction of respiration. The mutant strain had increased levels of COB RNA, suggestive that production of short CBP1 transcripts is a mechanism for downregulation of the levels of long CBP1 transcripts, Cbp1, and COB mRNA during the induction of respiration.

Editing of the grapevine mitochondrial cytochrome b mRNA and molecular modeling of the protein

Biochimie ◽  
2006 ◽  
Vol 88 (5) ◽  
pp. 431-435 ◽  
Author(s):  
María A. Islas-Osuna ◽  
Begonia Silva-Moreno ◽  
Nidia Caceres-Carrizosa ◽  
Jesús M. García-Robles ◽  
Rogerio R. Sotelo-Mundo ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Cytochrome B ◽  
Mitochondrial Cytochrome ◽  
Mitochondrial Cytochrome B ◽  
Cytochrome B Mrna

A novel nuclear gene, CBT1, essential for mitochondrial cytochrome b formation: terminal processing of mRNA and intron dependence

1997 ◽  
Vol 32 (3) ◽  
pp. 163-174 ◽  
Author(s):  
K.-J. Rieger ◽  
G. Aljinovic ◽  
Jaga Lazowska ◽  
Thomas M. Pohl ◽  
Piotr P. Slonimski
Keyword(s):  
Cytochrome B ◽  
Nuclear Gene ◽  
Mitochondrial Cytochrome ◽  
Mitochondrial Cytochrome B

scholarly journals Expression, purification, crystallization and preliminary X-ray crystallographic studies of a mitochondrial membrane-associated protein Cbs2 from Saccharomyces cerevisiae

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10901
Author(s):  
Dan Wu ◽  
Guanyu Zhu ◽  
Yufei Zhang ◽  
Yan Wu ◽  
Chunlei Zhang ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Cytochrome B ◽  
Diffraction Data ◽  
Mitochondrial Cytochrome ◽  
Inner Membrane ◽  
X Ray ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Cytochrome B ◽  
Cytochrome B Mrna

Background Mitochondria are unique organelles that are found in most eukaryotic cells. The main role of the mitochondria is to produce ATP. The nuclear genome encoded proteins Cbs1 and Cbs2 are located at the mitochondrial inner membrane and are reported to be essential for the translation of mitochondrial cytochrome b mRNA. Genetic studies show that Cbs2 protein recognizes the 5′ untranslated leader sequence of mitochondrial cytochrome b mRNA. However, due to a lack of biochemical and structural information, this biological process remains unclear. To investigate the structural characteristics of how Saccharomyces cerevisiae (S. cerevisiae) Cbs2 tethers cytochrome b mRNA to the mitochondrial inner membrane, a preliminary X-ray crystallographic study was carried out and is reported here. Methods The target gene from S. cerevisiae was amplified by polymerase chain reaction. The PCR fragment was digested by the NdeI and XhoI restriction endonucleases and then inserted into expression vector p28. After sequencing, the plasmid was transformed into Escherichia coli C43 competent cells. The selenomethionine derivative Cbs2 protein was overexpressed using M9 medium based on a methionine-biosynthesis inhibition method. The protein was first purified to Ni2+-nitrilotriacetate affinity chromatography and then further purified by Ion exchange chromatography and Gel-filtration chromatography. The purified Se-Cbs2 protein was concentrated to 10 mg/mL. The crystallization trials were performed using the sitting-drop vapor diffusion method at 16 °C. The complete diffraction data was processed and scaled with the HKL2000 package and programs in the CCP4 package, respectively. Results Cbs2 from S. cerevisiae was cloned, prokaryotic expressed and purified. The analysis of the size exclusion chromatography showed that the Cbs2 protein peaked at a molecular weight of approximately 90 KDa. The crystal belonged to the space group C2, with unit-cell parameters of a = 255.11, b = 58.10, c = 76.37, and β = 95.35°. X-ray diffraction data was collected at a resolution of 2.7 Å. The Matthews coefficient and the solvent content were estimated to be 3.22 Å 3 Da-1 and 61.82%, respectively. Conclusions In the present study Cbs2 from S. cerevisiae was cloned, expressed, purified, and crystallized for structural studies. The molecular weight determination results indicated that the biological assembly of Cbs2 may be a dimer.The preliminary X-ray crystallographic studies indicated the presence of two Cbs2 molecules in the asymmetric unit. This study will provide an experimental basis for exploring how Cbs2 protein mediates cytochrome b synthesis.

scholarly journals GENETIC CONTROL OF THE CELL DIVISION CYCLE IN YEAST: V. GENETIC ANALYSIS OF cdc MUTANTS

Genetics ◽  
1973 ◽  
Vol 74 (2) ◽  
pp. 267-286
Author(s):  
Leland H Hartwell ◽  
Robert K Mortimer ◽  
Joseph Culotti ◽  
Marilyn Culotti
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Nuclear Gene ◽  
Temperature Shift ◽  
Time Lapse ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Diploid Cells

ABSTRACT One hundred and forty-eight temperature-sensitive cell division cycle (cdc) mutants of Saccharomyces cerevisiae have been isolated and characterized. Complementation studies ordered these recessive mutations into 32 groups and tetrad analysis revealed that each of these groups defines a single nuclear gene. Fourteen of these genes have been located on the yeast genetic map. Functionally related cistrons are not tightly clustered. Mutations in different cistrons frequently produce different cellular and nuclear morphologies in the mutant cells following incubation at the restrictive temperature, but all the mutations in the same cistron produce essentially the same morphology. The products of these genes appear, therefore, each to function individually in a discrete step of the cell cycle and they define collectively a large number of different steps. The mutants were examined by time-lapse photomicroscopy to determine the number of cell cycles completed at the restrictive temperature before arrest. For most mutants, cells early in the cell cycle at the time of the temperature shift (before the execution point) arrest in the first cell cycle while those later in the cycle (after the execution point) arrest in the second cell cycle. Execution points for allelic mutations that exhibit first or second cycle arrest are rather similar and appear to be cistron-specific. Other mutants traverse several cycles before arrest, and its suggested that the latter type of response may reveal gene products that are temperature-sensitive for synthesis, whereas the former may be temperature-sensitive for function. The gene products that are defined by the cdc cistrons are essential for the completion of the cell cycle in haploids of a and α mating type and in a/α diploid cells. The same genes, therefore, control the cell cycle in each of these stages of the life cycle.

Sign in / Sign up

Export Citation Format

Share Document