Abstract
The effects of polyamines on the synthesis of various final sigma subunits of RNA polymerase were studied using Western blot analysis. Synthesis of final sigma(28) was stimulated 4.0-fold and that of final sigma(38) was stimulated 2.3-fold by polyamines, whereas synthesis of other final sigma subunits was not influenced by polyamines. Stimulation of final sigma(28) synthesis was due to an increase in the level of cAMP, which occurred through polyamine stimulation of the synthesis of adenylate cyclase at the level of translation. Polyamines were found to increase the translation of adenylate cyclase mRNA by facilitating the UUG codon-dependent initiation. Analysis of RNA secondary structure suggests that exposure of the Shine-Dalgarno sequence of mRNA is a prerequisite for polyamine stimulation of the UUG codon-dependent initiation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenylyl Cyclases / biosynthesis
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Adenylyl Cyclases / genetics*
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Base Sequence
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Codon
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Cyclic AMP / metabolism
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Cyclic AMP / pharmacology
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DNA-Directed RNA Polymerases / chemistry
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DNA-Directed RNA Polymerases / genetics*
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DNA-Directed RNA Polymerases / metabolism*
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Escherichia coli / enzymology*
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Escherichia coli / genetics*
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Escherichia coli / growth & development
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Kinetics
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Nucleic Acid Conformation
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Polyamines / pharmacology*
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Polymerase Chain Reaction
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Protein Biosynthesis / drug effects*
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Putrescine / pharmacology
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RNA, Bacterial / chemistry
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RNA, Bacterial / genetics
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RNA, Messenger / chemistry
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RNA, Messenger / genetics
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Recombinant Fusion Proteins / biosynthesis
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Recombinant Proteins / metabolism
Substances
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Codon
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Polyamines
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RNA, Bacterial
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RNA, Messenger
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Recombinant Fusion Proteins
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Recombinant Proteins
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Cyclic AMP
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RNA polymerase sigma(28)
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DNA-Directed RNA Polymerases
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Adenylyl Cyclases
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Putrescine