High levels of the mitochondrial large ribosomal subunit protein 40 prevent loss of mitochondrial DNA in nullmmf1 Saccharomyces cerevisiae cells

Yeast ◽  
2004 ◽  
Vol 21 (7) ◽  
pp. 539-548 ◽  
Author(s):  
Rosita Accardi ◽  
Ellinor Oxelmark ◽  
Nicolas Jauniaux ◽  
Vito de Pinto ◽  
Antonio Marchini ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Ribosomal Subunit ◽  
Large Ribosomal Subunit ◽  
Subunit Protein ◽  
Ribosomal Subunit Protein

scholarly journals Depletion of yeast ribosomal proteins L16 or rp59 disrupts ribosome assembly.

1990 ◽  
Vol 111 (6) ◽  
pp. 2261-2274 ◽  
Author(s):  
M Moritz ◽  
A G Paulovich ◽  
Y F Tsay ◽  
J L Woolford
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Proteins ◽  
Ribosomal Subunit ◽  
Ribosome Assembly ◽  
Ribosomal Rnas ◽  
Subunit Protein ◽  
40S Ribosomal Subunit ◽  
Ribosomal Subunit Protein ◽  
The Stability

Two strains of Saccharomyces cerevisiae were constructed that are conditional for synthesis of the 60S ribosomal subunit protein, L16, or the 40S ribosomal subunit protein, rp59. These strains were used to determine the effects of depriving cells of either of these ribosomal proteins on ribosome assembly and on the synthesis and stability of other ribosomal proteins and ribosomal RNAs. Termination of synthesis of either protein leads to diminished accumulation of the subunit into which it normally assembles. Depletion of L16 or rp59 has no effect on synthesis of most other ribosomal proteins or ribosomal RNAs. However, most ribosomal proteins and ribosomal RNAs that are components of the same subunit as L16 or rp59 are rapidly degraded upon depletion of L16 or rp59, presumably resulting from abortive assembly of the subunit. Depletion of L16 has no effect on the stability of most components of the 40S subunit. Conversely, termination of synthesis of rp59 has no effect on the stability of most 60S subunit components. The implications of these findings for control of ribosome assembly and the order of assembly of ribosomal proteins into the ribosome are discussed.

scholarly journals The male sterility-associated pcf gene and the normal atp9-1 gene in Petunia are located on different mitochondrial DNA molecules.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 885-895
Author(s):  
O Folkerts ◽  
M R Hanson
Keyword(s):  
Mitochondrial Dna ◽  
Male Sterility ◽  
Nadh Dehydrogenase ◽  
Ribosomal Subunit ◽  
Cms Line ◽  
Ribosomal Subunit Protein ◽  
Mtdna Organization ◽  
Relationship Of ◽  
The Relationship ◽  
Functional Copy

Abstract A mitochondrial DNA (mtDNA) region termed the S-pcf locus has previously been correlated with cytoplasmic male sterility (CMS) in Petunia. In order to understand the relationship of the S-pcf locus to homologous sequences found elsewhere in mtDNAs of both CMS and fertile lines, the structure of the mitochondrial genome of CMS Petunia line 3688 was determined by cosmid walking. The S-pcf locus, which includes the only copies of genes for NADH dehydrogenase subunit 3 (nad3) and small ribosomal subunit protein 12 (rps12) was found to be located on a circular map of 396 kb, while a second almost identical circular map of 407 kb carries the only copies of the genes for 18S and 5S rRNA (rrn18 and rrn5), the only copy of a conserved unidentified gene (orf25), and the only known functional copy of atp9. Three different copies of a recombination repeat were found in six genomic environments, predicting sub-genomic circles of 277, 266 and 130 kb. The ratio of atp9 to S-pcf mtDNA sequences was approximately 1.5 to 1, indicating that sub-genomic molecules carrying these genes differ in abundance. Comparison of the mtDNA organization of the CMS line with that of the master circle of fertile Petunia line 3704 reveals numerous changes in order and orientation of ten different sectors.

Identification of the Escherichia coli 30S ribosomal subunit protein neighboring mRNA during initiation of translation

Biochimie ◽  
1992 ◽  
Vol 74 (4) ◽  
pp. 363-371 ◽  
Author(s):  
O.A. Dontsova ◽  
K.V. Rosen ◽  
S.L. Bogdanova ◽  
E.A. Skripkin ◽  
A.M. Kopylov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Subunit ◽  
Subunit Protein ◽  
Initiation Of Translation ◽  
Ribosomal Subunit Protein

scholarly journals CAT tails drive on- and off-ribosome degradation of stalled polypeptides

2018 ◽  
Author(s):  
Cole S. Sitron ◽  
Onn Brandman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Quality Control ◽  
Ubiquitin Ligase ◽  
Ribosomal Subunit ◽  
Protein Homeostasis ◽  
Large Ribosomal Subunit ◽  
Backup Route ◽  
Carboxy Terminal

SummaryStalled translation produces incomplete, ribosome-associated polypeptides that Ribosome-associated Quality Control (RQC) targets for degradation via the ubiquitin ligase Ltn1. During this process, the Rqc2 protein and large ribosomal subunit elongate stalled polypeptides with carboxy-terminal alanine and threonine residues (CAT tails). Failure to degrade CAT-tailed proteins disrupts global protein homeostasis, as CAT-tailed proteins aggregate and sequester chaperones. Why cells employ such a potentially toxic process during RQC is unclear. Here, we developed quantitative techniques to assess how CAT tails affect stalled polypeptide degradation in Saccharomyces cerevisiae. We found that CAT tails improve Ltn1’s efficiency in targeting structured polypeptides, which are otherwise poor Ltn1 substrates. If Ltn1 fails, CAT tails undergo a backup route of ubiquitylation off the ribosome, mediated by the ubiquitin ligase Hul5. Thus, CAT tails functionalize the carboxy-termini of stalled polypeptides to drive their degradation on and off the ribosome.

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