Increase of Cytochrome b mRNA by Bis(2-hydroxyethyl) Trisulfide in J774A.1 Cells.

1996 ◽  
Vol 19 (6) ◽  
pp. 876-878 ◽  
Author(s):  
Yasuhiro KOHAMA ◽  
Kentaro IIDA ◽  
Susumu ITOH ◽  
Kazutake TSUJIKAWA ◽  
Tsutomu MIMURA
1997 ◽  
Vol 17 (8) ◽  
pp. 4199-4207 ◽  
Author(s):  
K A Sparks ◽  
S A Mayer ◽  
C L Dieckmann

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.


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 ◽  
...  

1997 ◽  
Vol 17 (11) ◽  
pp. 6203-6211 ◽  
Author(s):  
W Chen ◽  
C L Dieckmann

The cytochrome b (COB) gene is encoded by the mitochondrial genome; however, its expression requires the participation of several nuclearly encoded protein factors. The yeast Cbp1 protein, which is encoded by the nuclear CBP1 gene, is required for the stabilization of COB mRNA. A previous deletion analysis identified an 11-nucleotide-long sequence within the 5' untranslated region of COB mRNA that is important for Cbp1-dependent COB mRNA stability. In the present study, site-directed mutagenesis experiments were carried out to define further the features of this cis element. The CCG sequence within this region was shown to be necessary for stability. A change in residue 533 of Cbp1 from aspartate to tyrosine suppresses the effects of a single-base change in the CCG element. This is strong genetic evidence that the nuclearly encoded Cbp1 protein recognizes and binds directly to the sequence containing CCG and thus protects COB mRNA from degradation.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10901
Author(s):  
Dan Wu ◽  
Guanyu Zhu ◽  
Yufei Zhang ◽  
Yan Wu ◽  
Chunlei Zhang ◽  
...  

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.


Genetics ◽  
1994 ◽  
Vol 138 (3) ◽  
pp. 565-575
Author(s):  
R R Staples ◽  
C L Dieckmann

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.


1997 ◽  
Vol 9 (3) ◽  
pp. 167-176 ◽  
Author(s):  
Nuo-Yu Huang ◽  
Marina Strakhova ◽  
Richard T. Layer ◽  
Phil Skolnick

Cell ◽  
1980 ◽  
Vol 19 (2) ◽  
pp. 321-329 ◽  
Author(s):  
A. Halbreich ◽  
P. Pajot ◽  
M. Foucher ◽  
C. Grandchamp ◽  
P. Slonimski

1994 ◽  
Vol 267 (3) ◽  
pp. E388-E395 ◽  
Author(s):  
T. Murakami ◽  
Y. Shimomura ◽  
N. Fujitsuka ◽  
N. Nakai ◽  
S. Sugiyama ◽  
...  

To evaluate the effects of physical training on mitochondrial gene expression and mitochondrial biogenesis in slow-twitch muscle, adult female Sprague-Dawley rats were trained for 3, 6, and 12 wk by running on a motor-driven treadmill (speed of 25 m/min and duration of 90 min/day, 5 days/wk), and the activities of citrate synthase, ubiquinol-cytochrome-c oxidoreductase, cytochrome oxidase, mitochondrial cytochrome b mRNA (by Northern blot analysis), and mitochondrial DNA (by slot-blot and Southern blot analyses) were measured in rat soleus muscle. A DNA probe for detection of mitochondrial mRNA and DNA was prepared from a 1,500-bp fragment of human mitochondrial DNA that included the coding region of the cytochrome b gene. Training for 3, 6, and 12 wk significantly increased the activities of citrate synthase (31, 28, and 47%, respectively), ubiquinol-cytochrome-c oxidoreductase (61, 63, and 77%, respectively), and cytochrome oxidase (25, 26, and 32%, respectively) in muscle. The concentration of cytochrome b mRNA in the muscle was proportionally elevated with the enzyme activities. On the other hand, the mitochondrial DNA concentration in the muscle was not altered by training for 3 or 6 wk but increased significantly after training for 12 wk (35% in the slot-blot analysis and 31% in the Southern blot analysis). These results suggest that an increase in the oxidative capacity of slow-twitch muscle by the relatively short-term training is regulated at the pretranslational step in mitochondrial protein synthesis but that the increase by the long-term training involves mitochondrial replication.


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