FIG. 4.

(A) Western blotting for InvE and IpaB proteins in S. sonnei strains. Lanes: cpxR, MS2830; cpxA, MS2824; Wt, MS390; −, MS2824 carrying pACYC177; +, MS2824 carrying pJM0329. The lowest band indicates a cross-reacting irrelevant protein detected by the InvE polyclonal antibody as a loading control (L/C). (B) Northern blotting for virF and invE mRNAs. Total RNA was purified from cpxA (MS2824) and wild-type (MS390) strains in the same cultures as those used in panel A. Either 18 or 4 μg of total RNA was loaded for the blotting of virF (left panel) and invE (middle panel), respectively. The right panel indicates the ethidium bromide-stained RNA pattern after electrophoresis in a 1% agarose gel to detect virF mRNA.