The C1q binding to immunoglobulins within immunocomplexes initiates the classic complement cas cade and pathogen elimination. In the presence of Ca ions, the interaction of self and non self ligands with charged gC1q residues causes gC1q reorientation and bending of the collagenous region. The activation signal is then transmitted to serine protease precursors which, in turn, promote the proteolytic comple ment cascade and formation of a membrane attack com plex. Overall, the modularity and versatility of pattern recognition confirm the essential role of gC1q in both innate and acquired immune responses. Several MGCs display Inhibitors,Modulators,Libraries sequence similarity to C1q, TNF, precerebellin, collagen and emilin proteins. Searching the TNF like domain IPR008983 in Mytibase, we identified 146 transcripts, most of which Inhibitors,Modulators,Libraries are also characterized by the C1q domain IPR001073.

Hidden Markov model analysis allowed the recognition of 22 additional C1q containing sequences and the C1q motif was confirmed by manual validation in all 168 cases, without evidence of a true TNF domain. To illustrate their molecular diversity, a selection Entinostat of the most diver gent C1q containing MGCs is reported in Figure 2. Many of them are similar to a sequence highly expressed in the Inhibitors,Modulators,Libraries mantle of the oyster Pinctada fucata and some are very abundant, for instance MGC0284 with 99 out of 109 ESTs originating from hemocyte cDNAs. In addition to the C terminal globular domain, most of the predicted C1q proteins of M.

galloprovincialis have a short N terminal signal peptide but lack central col lagen like repeats, hence, they should represent secreted gC1q receptor proteins expected to elicit chemotaxis Inhibitors,Modulators,Libraries and pathogen lysis via more ancient complement path ways. The abundance and molecular diversity of the C1q containing transcripts of M. galloprovincialis sug gest pathogen induced expansion of lectin like PRR, the identification of related gene sequences will allow a comparison with the 32, 52 and 75 C1q gene models reported in Homo sapiens, Danio rerio and in the amphioxus Brachiostoma floridae, respectively. The new microarray platform includes 162 of these mussel transcripts and also a few mussel transcripts similar to the complement component C3 and a Membrane attack complex perforin C9 expected to be involved in the pathogen lysis. Additional lectin like and receptor related transcripts Protein carbohydrate recognition is crucial to many cell processes and host pathogen interactions. Lectins are membrane associated and soluble proteins with specific carbohydrate recognition domains which can either facilitate mutualistic interactions between host and microbiota or initiate innate and adaptive immune responses.