Chitin, an insoluble polymer of GIcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GIcNAc)2-6, GIcNAc, or the glucosamine dimer (GIcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GIcNAc)2-6 gene set, including a (GIcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PiIA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GIcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GIcNAc; (iii) (GIcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin.
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Number of pages||6|
|Publication status||Published - 2004|