Differential expression of protein S genes during Myxococcus xanthus development.

AUTOR(ES)
RESUMO

Protein S, the most abundant protein synthesized during development of the fruiting bacterium Myxococcus xanthus, is coded by two highly homologous genes called protein S gene 1 (ops) and protein S gene 2 (tps). The expression of these genes was studied with fusions of the protein S genes to the lacZ gene of Escherichia coli. The gene fusions were constructed so that expression of beta-galactosidase activity was dependent on protein S gene regulatory sequences. Both the gene 1-lacZ fusion and the gene 2-lacZ fusion were expressed exclusively during fruiting body formation (development) in M. xanthus. However, distinct patterns of induction of fusion protein activity were observed for the two genes. Gene 2 fusion activity was detected early during development on an agar surface and could also be observed during nutritional downshift in dispersed liquid culture. Gene 1 fusion activity was not detected until much later in development and was not observed after downshift in liquid culture. The time of induction of gene 1 fusion activity was correlated with the onset of sporulation, and most of the activity was spore associated. This gene fusion was expressed during glycerol-induced sporulation when gene 2 fusion activity could not be detected. The protein S genes appear to be members of distinct regulatory classes of developmental genes in M. xanthus.

Documentos Relacionados