EXPRESSION AND FUNCTION OF N GONORRHEAE PILUS PROTEINS

Many microorganisms produce pili or firmbriae on their cell surface. The
proteins vary in functon depending on the organism. In many cases these
surface structures enable the bacterium to adhere to their host or organism
they subsequently interact with. Thus these surface structures play a
primary role in host-parasite interaction. The pili produced by Neisseria
gonorrhoeae are no exception. These pili function in the attachment of the
gonococci to the human host and therefore is a primary determinant of
pathogenicity, a major factor in cell-cell interaction. The gene(s)
encoding pilus synthesis is turned on and off at high frequency. The
phenotypes (P+ and P-) can be determined easily by light microscopy. There
are at least 50 pili serotypes. The heterogeneity lies at the
carboxyterminal end; the amino terminal end for the pilus subunit is very
similar if not identical. Very little is known about the genetic
regulation of pili expression in N. gonorrhoeae. For these reasons, the
pili of the gonococci represent an interesting system for studying the
regulation of gene expression. We propose to study the basis for pilus expression in N. gonorrhoeae.
Using techniques in genetics (mutagenesis and complementation), DNA
biochemistry (recombinant cloning, DNA sequencing, Southern hybridization),
protein chemistry (SDS PAGE, 2-dimensional gels, Western blotting) and
immunology (immunoprecipitation) we hope to elucidate the mechanism
underlying the heterogeneity of pilus type as well as the genetic and
molecular mechanisms regulating the expression of pili synthesis by the
gonococcus.