Disease relevance of ipaD

• As shigellae expressing ipaD N-terminal deletion mutations have reduced contact-mediated hemolysis activity and are less efficient at introducing IpaB and IpaC into erythrocyte membranes, it is possible that IpaD is responsible for insertion of IpaB/IpaC pores into target cell membranes [1].
• The products of the ipaB, ipaC, and ipaD genes are involved in the expression of the invasive phenotype in all species of Shigella and enteroinvasive Escherichia coli (EIEC) [2].

High impact information on ipaD

• Using lacZ transcriptional fusions, we found that transcription of virA and four ipaH genes, but not that of the ipaBCDA and mxi operons, was markedly increased during growth in the presence of Congo red and in an ipaD mutant, two conditions in which secretion through the Mxi-Spa machinery is enhanced [3].
• Here, we show that ipaB and ipaD mutations lead to enhanced secretion of a set of about 15 proteins [4].
• Furthermore, both delta ipaC hly(low) and delta ipaD hly(low) killed through apoptosis as shown by both changes in ultrastructural morphology and fragmentation of the host cell DNA [5].
• The DNA sequences of S. dysenteriae ipaBC genes were very similar to those of S. flexneri M90T and S. flexneri YSH6000, but ipaD differed by 22 codons from that of S. flexneri [6].
• The 4.0 kb RNA was the transcript for the operon encoding the 24, 18 kD, IpaB and C proteins and the 4.5 kb RNA for the ipaD gene [7].

Other interactions of ipaD

• Genes ipaB, ipaC and ipaD mapped to contiguous 4.6-kilobase (kb) and 1.0-kb HindIII fragments contained within a larger (23-kb) BamHI fragment [8].

Analytical, diagnostic and therapeutic context of ipaD

• To overcome the lack of specificity for individual antigens in the water-extract enzyme-linked immunosorbent assay (ELISA), the ipaD gene from S. flexneri has been cloned, expressed to a high level, and purified for use in a new ELISA for the determination of the levels of antibody against IpaD in monkeys and humans challenged with shigellae [9].

References