CspI, the ninth member of the CspA family of Escherichia coli, is induced upon cold shock.
Escherichia coli contains the CspA family, consisting of nine proteins (CspA to CspI), in which CspA, CspB, and CspG have been shown to be cold shock inducible and CspD has been shown to be stationary-phase inducible. The cspI gene is located at 35.2 min on the E. coli chromosome map, and CspI shows 70, 70, and 79% identity to CspA, CspB, and CspG, respectively. Analyses of cspI-lacZ fusion constructs and the cspI mRNA revealed that cspI is cold shock inducible. The 5'-untranslated region of the cspI mRNA consists of 145 bases and causes a negative effect on cspI expression at 37 degrees C. The cspI mRNA was very unstable at 37 degrees C but was stabilized upon cold shock. Analyses of the CspI protein on two-dimensional gel electrophoresis revealed that CspI production is maximal at or below 15 degrees C. Taking these results together, E. coli possesses a total of four cold shock-inducible proteins in the CspA family. Interestingly, the optimal temperature ranges for their induction are different: CspA induction occurs over the broadest temperature range (30 to 10 degrees C), CspI induction occurs over the narrowest and lowest temperature range (15 to 10 degrees C), and CspB and CspG occurs at temperatures between the above extremes (20 to 10 degrees C).
Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854, USA.
N
N
Wang
K
K
Yamanaka
M
M
Inouye
D020121:5' Untranslated Regions / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D003080:Cold Temperature; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics; D001616:beta-Galactosidase / Q000235:genetics
D020121:5' Untranslated Regions; D001426:Bacterial Proteins; D002352:Carrier Proteins; C491179:CspB protein, E coli; C118134:CspG protein, E coli; C118133:CspI protein, E coli; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C062260:cold shock protein CS7.4, Bacteria; C077188:cold-shock protein CspB, Bacteria; D001616:beta-Galactosidase