This gene is a member of the Regulator of Complement Activation (RCA) gene cluster and encodes a protein with twenty short concensus repeat (SCR) domains. This protein is secreted into the bloodstream and has an essential role in the regulation of complement activation, restricting this innate defense mechanism to microbial infections. Mutations in this gene have been associated with hemolytic-uremic syndrome (HUS) and chronic hypocomplementemic nephropathy. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.
Expression regulated by
Cumulus, Granulosa, Follicular Fluid
The human cumulus-oocyte complex gene-expression profile. Assou S et al. BACKGROUND: The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes and cumulus cells.
Proteome mining of human follicular fluid reveals a crutial role of complement cascade and key biological pathways in women undergoing in vitro fertilisation. Jarkovska K et al. In vitro fertilisation (IVF) is fraught with problems and currently proteomics approaches are being tried out to examine the microenvironment of the follicle in order to assess biological and immunological parameters that may affect its development. Additionaly, better understanding of reproductive process may help increase IVF birth rate per embryo transfer and at the same time avoid spontaneous miscarriages or life threatening conditions such as ovarian hyperstimulation syndrom. The primary aim of this study was to search for specific differences in protein composition of human follicular fluid (HFF) and plasma in order to identify proteins that accumulate or are absent in HFF. Depletion of abundant proteins combined with multi-dimensional protein fractionation allowed the study of middle and lower abundant proteins. Paired comparison study examining HFF with plasma/serum from women undergoing successful IVF revealed important differences in the protein composition which may improve our knowledge of the follicular microenvironment and its biological role. This study showed involvement of innate immune function of complement cascade in HFF. Complement inhibition and the presence of C-terminal fragment of perlecan suggested possible links to angiogenesis which is a vital process in folliculogenesis and placental development. Differences in proteins associated with blood coagulation were also found in the follicular milieu. Several specific proteins were observed, many of which have not yet been associated with follicle/oocyte maturation. These proteins together with their regulatory pathways may play a vital role in the reproductive process.
Complement factors are secreted in human follicular fluid by granulosa cells and are possible oocyte maturation factors. Yoo SW et al. Aims: In this study, we identify components of the complement system present in human follicular fluid that affect oocyte development and maturation. Material and Methods: Using bottom-up liquid chromatography/mass spectrometry/mass spectrometry, we identified complement factors as consistently present in human follicular fluid from 15 different subjects. Results: According to our gene-chip data, these complement factors are actively produced by granulosa cells. Conclusions: By applying the computational Ingenuity Pathway Analysis software and database we have identified complement pathways that play a role in oocyte maturation and follicular development.