the biography of ribonuclease p
DESCRIPTION
The Biography of Ribonuclease P. Marta Wegorzewska Macromolecules 5.7.09. www.physorg.com/news144947904.html. Discovery: pre-tRNA. 1971: Precursor t-RNA. Sidney Altman. www.oisb.ca/.../pic_members_Sidney_Altman.jpg. Altman et al., 1971. 41 nt at 5’ end. Discovery: . 3 nt at 3’ end. - PowerPoint PPT PresentationTRANSCRIPT
The Biography of Ribonuclease P
Marta WegorzewskaMacromolecules
5.7.09
www.physorg.com/news144947904.html
Discovery: pre-tRNA
Sidney Altman
Altman et al., 1971
1971: Precursor t-RNA
www.oisb.ca/.../pic_members_Sidney_Altman.jpg
Discovery:
Altman et al., 1971
41 nt at 5’ end3 nt at 3’ end
Isolation and purification of pre-tRNA
Discovery:
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Evans et al., 2006
Altman et al., 1971
--------> Nuclear extracts of E.coli
RNase P
Discovery: purification of RNase P
Robertson et al., 1972
Purifying RNase P Actions of purified RNase P
1972:
Discovery: RNase P: RNA-protein mix
Stark et al., 1978
1978: Benjamin Stark (graduate student) identified the RNA and protein subunit of E.coli RNase P
M2: methylene blue staining for nucleic acid stain
C5: Coomassie brilliant blue staining for protein
Discovery: RNase P: a ribonuclease and ribozyme
6= E.coli RNA + protein
7= E.coli RNA (M1 RNA)
8= E.coli protein (C5)
Pre-tRNA
Mature tRNA
1983: Cecilia Guerrier-Takada
Guerrier-Takada et al., 1983
Conservation: RNA
Evans et al., 2006
Conservation: Protein
Hartmann et al., 2003Bacteria
Summary:
Bacteria Archaea Eukarya
RNA-
Protein-
E.coliM1 RNA; type A (ancestral) B. sub type B (Bacillus)
M. the. one RNA subunit
H. sap.
H1 RNA
E.coli one protein: C5 B. sub one protein: P protein
M. the. 4 proteins: Pop4, Rpr2, Rpp1, Pop5
H. sap.
10 proteins: hPop1, Rpp29, Rpp21, Rpp30, hPop5, Rpp14, Rpp20, Rpp25, Rpp40, Rpp38
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Hall et al., 2002
Function: ribonuclease
www.science.ca/images/altman_rnase.jpg
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Rnase P, Mg2+
Evans et al., 2006
RNase P functions to remove extraneous 5' sequences from precursor tRNAs to generate mature tRNA
Mechanism of Action:
1. Pre-tRNA binding to S and C domains of RNase P RNA subunit
2. RNase P protein subunit binding to 5’ end of pre-tRNA
Function: Human Rnase P: a transcription factor
Jarrous et al., 2007
RNase P protein found at 5S rRNA, 7SL RNA and U6 snRNA genes (non-RNase P substrate genes) and tRNA genes (RNase P substrate genes)
Potential as a tool: potential as a antibacterial, antiviral and anticancer agent
Can we take advantage of the catalytic function of M1RNA to target bacterial, viral, oncogenic mRNAs??
Cobaleda et al., 2001
Guide sequences (GS): External guide sequences (EGS): exogenous GS recruits endogenous RNase P
Internal guide sequences (IGS): GS covalently linked to M1RNA (M1GS)Requirements:
1. Complementary to target mRNA
2. 3’ sequence for recognition by M1 RNA (EGS)
Cobaleda et al., 2001
Application: Anti-bacterial potential: Guerrier-Takada et al. 1995 showed specific targeting of EGS to B-galactosidase and alkaline phosphatase encoding genes (expressions were decreased by 50-60% in E.coli)Anti-viral potential: IGS and EGS used to target herpes simplex virus 1 (HSV-1), human immunodeficiency virus (HIV), human influenza virus, human cytomegalovirus and Kaposi's sarcoma-associated herpesvirus
Cobaleda et al., 2001
Anti-cancer potential: M1GS used for destruction of chimeric mRNAs created by chromosomal translocation (BCR-ABL)
Application:Anti-cancer potential:
Ba/F3 cells expressing the human BCR-ABLp190
+
M1GS against BCR-ABL p190Cobaledo et al., 2000
Application: advantages for basic science research
This sounds awesome! Why don’t hear about it as a tool for used in gene knockdown studies?
Advantages of EGS/M1GS:
1. EGS uses endogenous RNase P (most abundant, stable and efficient enzymes) resulting in irreversible cleavage of target mRNA
2. Highly specific and does not mistarget (RNA i) 3. Little sign of cytotoxicity
RNA interference
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