Cloning and characterisation of CrSARM, a novel signaling molecule responsive to pseudomonas infection

Abstract

Sterile alpha and Armadillo motif containing protein (SARM) is recently identified as an essential immune-related signaling molecule. Its exact roles in host defense against microbial infection, however, remain unclear. An EST clone of the horseshoe crab, Carcinoscopius rotundicauda SARM (CrSARM) was isolated from genes that are differentially regulated in the amebocytes in response to Pseudomonas aeruginosa infection. CrSARM shows high homology to the homologs from the worm, fly and mammals. Using yeast two-hybrid screening, potential interaction partners of CrSARM were identified to be CaMKI, SUMO-1, HAX-1, proteasome-i?! subunit, and Hsp40. Our result suggests the potential roles of CrSARM in the TLR-mediated calcium-dependent signaling cascade leading to the activation of p38 kinase and the regulation of cytoskeletal remodeling and/or apoptosis, as well as the proteasomal degradation and the chaperone machinery. The outcomes of these signaling events are crucial for various immunological as well as physiological processes, hence our understanding of host-pathogen interaction.