The heat shock response of type 1 and type 4 gonococci

A heat shock response, characterized by the elevated expression of certain proteins in response to a shift to a higher temperature, has been observed in both eukaryotic and prokaryotic organisms. We have characterized the heat shock response of the pathogenic organism N. gonorrhoeae, colony types 1 and 4. Following a shift up in temperature from 37 C to 43 C, two-dimensional gel electrophoretic analysis was used to identify 19 heat shock proteins in Type 1 and 37 heat shock proteins in Type 4 gonococci. One heat shock protein was found only in Type 1, 19 were common to both Type 1 and Type 4, and 19 were found only in Type 4 gonococci. Most heat shock proteins were found in the cytoplasm, some in the cytoplasmic membrane, and none could be detected in the outer membrane. Pulse-chase experiments revealed that heat shock proteins were very stable.