Annual Report 2011 - Center for Advanced Biotechnology and ...

mRNA interferases
mRNA interferases are encoded by one of the TA systems. MazF from E. coli is
the first mRNA interferase discovered in Dr. Inouye’s laboratory and functions as
a sequence-specific (ACA) endoribonuclease. Its induction in E. coli cells results
in growth arrest and eventual cell death. The Inouye group also observed that
MazF induction in mammalian cells effectively causes Bak (a pro-apoptotic
protein)-dependent programmed cell death. The application of bacterial mRNA
interferases for mammalian cell growth regulation is currently being explored to
develop an effective, novel method for cancer treatment and HIV eradication. In
addition to E. coli MazF, the laboratory has identified a large number of mRNA
interferases having different RNA cleavage specificity, including one from a
highly halophilic archaeon that cleaves a specific seven base sequence. mRNA
interference using highly sequence-specific mRNA interferases instead of
antisense RNA or RNAi may be a novel and exciting way to regulate gene
expression.
Single protein production in living cells
Expression of MazF, an ACA-specific mRNA interferase, results in nearly
complete degradation of cellular mRNAs, leading to almost complete inhibition
of protein synthesis. Intriguingly, MazF-induced cells are still fully capable of
producing a protein at a high level if the mRNA for that protein is engineered to
have no ACA sequences without altering its amino acid sequence. Therefore, it is
possible to convert E. coli cells into a bioreactor producing a single protein of
interest. This “single-protein production” (SPP) system allows NMR structural
studies of proteins without purification, which makes this system especially useful
for structural studies of membrane proteins. In addition, the SPP system provides
a unique opportunity to produce proteins in which all the residues of a specific
amino acid in a protein are replaced with toxic non-natural amino acid analogues
to create proteins of novel structures and functions.
Publications:
Awano, N., Rajagopal, V., Arbing, M., Patel, S., Hunt, J., Inouye, M., Phadtare, S.
Escherichia coli RNase R has dual activities, helicase and ribonuclease. J.
Bacteriol. 2010 192(5):1344-52.
Peng, Y.Y., Yoshizumi, A., Danon, S.J., Glattauer, V., Prokopenko, O.,
Mirochinitchenko, O., Yu, Z., Inouye, M., Werkmeister, J.A., Brodsky, B.,
Ramshaw, J.A. A Streptococcus pyogenes derived collagen-like protein as a noncytotoxic
and non-immunogenic cross-linkable biomaterial. Biomaterials 2010
31(10):2755-61.
Jung-Ho Park
Graduate Student
Narumi Tokunaga
Graduate Student
Zhuoxin Yu
Graduate Student
Dr. Qian Tan
Research Teaching Spec.
Chun Ying Xu
Research Teaching Spec.
Dr. Yoshihiro
Yamaguchi
Research Teaching Spec.
Dr. Yong Long Zhang
Research Teaching Spec.
Xushen Chen
Lab Technician
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