scholarly journals Introns within Ribosomal Protein Genes Regulate the Production and Function of Yeast Ribosomes

Cell ◽  
2011 ◽  
Vol 147 (2) ◽  
pp. 320-331 ◽  
Author(s):  
Julie Parenteau ◽  
Mathieu Durand ◽  
Geneviève Morin ◽  
Jules Gagnon ◽  
Jean-François Lucier ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Protein Genes ◽  
Yeast Ribosomes ◽  
And Function

Structure and expression of ribosomal protein genes in Xenopus laevis

1995 ◽  
Vol 73 (11-12) ◽  
pp. 969-977 ◽  
Author(s):  
Francesco Amaldi ◽  
Olga Camacho-Vanegas ◽  
Francesco Cecconi ◽  
Fabrizio Loreni ◽  
Beatrice Cardinali ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Translational Regulation ◽  
Cultured Cells ◽  
Structural Features ◽  
Ribosomal Protein Genes ◽  
Translation Apparatus ◽  
And Function

In Xenopus laevis, as well as in other vertebrates, ribosomal proteins (r-proteins) are coded by a class of genes that share some organizational and structural features. One of these, also common to genes coding for other proteins involved in the translation apparatus synthesis and function, is the presence within their introns of sequences coding for small nucleolar RNAs. Another feature is the presence of common structures, mainly in the regions surrounding the 5′ ends, involved in their coregulated expression. This is attained at various regulatory levels: transcriptional, posttranscriptional, and translational. Particular attention is given here to regulation at the translational level, which has been studied during Xenopus oogenesis and embryogenesis and also during nutritional changes of Xenopus cultured cells. This regulation, which responds to the cellular need for new ribosomes, operates by changing the fraction of rp-mRNA (ribosomal protein mRNA) engaged on polysomes. A typical 5′ untranslated region characterizing all vertebrate rp-mRNAs analyzed to date is responsible for this translational behaviour: it is always short and starts with an 8–12 nucleotide polypyrimidine tract. This region binds in vitro some proteins that can represent putative trans-acting factors for this translational regulation.Key words: ribosomal proteins, snoRNA, translational regulation, Xenopus laevis.

Protein kinase A mediates growth-regulated expression of yeast ribosomal protein genes by modulating RAP1 transcriptional activity

1994 ◽  
Vol 14 (3) ◽  
pp. 1920-1928
Author(s):  
C Klein ◽  
K Struhl
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Carbon Source ◽  
Ribosomal Protein ◽  
Binding Sites ◽  
Transcriptional Activity ◽  
Amino Acid Starvation ◽  
Ribosomal Protein Genes ◽  
Regulated Expression ◽  
Kinase A

Yeast ribosomal protein genes are coordinately regulated as a function of cell growth; RNA levels decrease during amino acid starvation but increase following a carbon source upshift. Binding sites for RAP1, a multifunctional transcription factor, are present in nearly all ribosomal protein genes and are associated with growth rate regulation. We show that ribosomal protein mRNA levels are increased twofold in strains that have constitutively high levels of cyclic AMP-dependent protein kinase (protein kinase A [PKA]) activity. The PKA-dependent induction requires RAP1 binding sites, and it reflects increased transcriptional activation by RAP1. Growth-regulated transcription of ribosomal protein genes strongly depends on the ability to regulate PKA activity. Cells with constitutively high PKA levels do not show the transcriptional decrease in response to amino acid starvation. Conversely, in cells with constitutively low PKA activity, ribosomal protein mRNAs levels are lower and largely uninducible upon carbon source upshift. We suggest that modulation of RAP1 transcriptional activity by PKA accounts for growth-regulated expression of ribosomal protein genes.

Yeast ribosomal protein L1 is required for the stability of newly synthesized 5S rRNA and the assembly of 60S ribosomal subunits

1993 ◽  
Vol 13 (5) ◽  
pp. 2835-2845
Author(s):  
M Deshmukh ◽  
Y F Tsay ◽  
A G Paulovich ◽  
J L Woolford
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Subunit ◽  
Single Copy ◽  
5S Rrna ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Ribosomal Protein L1 ◽  
The Stability ◽  
And Function

Ribosomal protein L1 from Saccharomyces cerevisiae binds 5S rRNA and can be released from intact 60S ribosomal subunits as an L1-5S ribonucleoprotein (RNP) particle. To understand the nature of the interaction between L1 and 5S rRNA and to assess the role of L1 in ribosome assembly and function, we cloned the RPL1 gene encoding L1. We have shown that RPL1 is an essential single-copy gene. A conditional null mutant in which the only copy of RPL1 is under control of the repressible GAL1 promoter was constructed. Depletion of L1 causes instability of newly synthesized 5S rRNA in vivo. Cells depleted of L1 no longer assemble 60S ribosomal subunits, indicating that L1 is required for assembly of stable 60S ribosomal subunits but not 40S ribosomal subunits. An L1-5S RNP particle not associated with ribosomal particles was detected by coimmunoprecipitation of L1 and 5S rRNA. This pool of L1-5S RNP remained stable even upon cessation of 60S ribosomal subunit assembly by depletion of another ribosomal protein, L16. Preliminary results suggest that transcription of RPL1 is not autogenously regulated by L1.

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