The large household of proteins that has a C1q domain support lots of biological processes, from complement activation, modulatory immune func tions, apoptotic cell clearance to coagulation, embryonic growth and tissue homeostasis. In mammals, the 18 polypeptide chains composing the complement subcomponent C1q are characterized by a short N terminal region, a collagen like Gly/Pro wealthy tract in addition to a C terminal tulip like construction of globular C1q domains also found in ficolins and other proteins. The C1q binding to immunoglobulins within immunocomplexes initiates the classic complement cas cade and pathogen elimination. During the presence of Ca ions, the interaction of self and non self ligands with charged gC1q residues leads to gC1q reorientation and bending within the collagenous region. The activation signal is then transmitted to serine protease precursors which, in flip, promote the proteolytic comple ment cascade and formation of the membrane assault com plex.
Total, the modularity and versatility of pattern recognition confirm the very important function of gC1q in the two innate and acquired immune responses. A number of MGCs display sequence similarity to C1q, TNF, precerebellin, collagen and emilin proteins. Looking the TNF like domain IPR008983 in Mytibase, we identified 146 transcripts, almost all of which are also characterized by the C1q domain selleck chemicals IPR001073. Hidden Markov model analysis allowed the recognition of 22 supplemental C1q containing sequences plus the C1q motif was confirmed by manual validation in all 168 instances, without evidence of the real TNF domain. To illustrate their molecular diversity, a choice of the most diver gent C1q containing MGCs is reported in Figure two. A lot of them are just like a sequence highly expressed from the mantle within the oyster Pinctada fucata and some are extremely abundant, as an illustration MGC0284 with 99 from 109 ESTs originating from hemocyte cDNAs.
In addition to the JNJ-1661010 C terminal globular domain, the vast majority of the predicted C1q proteins of M. galloprovincialis have a quick N terminal signal peptide but lack central col lagen like repeats, therefore, they will need to represent secreted gC1q receptor proteins expected to elicit chemotaxis and pathogen lysis via even more ancient complement path methods. The abundance and molecular diversity of the C1q containing transcripts of M. galloprovincialis sug gest pathogen induced growth of lectin like PRR. the identification of related gene sequences
will allow a comparison with the 32, 52 and 75 C1q gene versions reported in Homo sapiens, Danio rerio and from the amphioxus Brachiostoma floridae, respectively. The new microarray platform contains 162 of those mussel transcripts and also some mussel transcripts similar to the complement part C3 and a Membrane attack complex/perforin/ C9 expected to be involved with the pathogen lysis.