Post-transcriptional regulation of complement C4 in low C4-producing strain of mouse
The expression of the fourth component of complement (C4) of the mouse can differ 20-fold and is determined byC4-high (C4 h ) orC4-low (C4 l ) alleles. To investigate the molecular mechanisms underlying the differences in C4 expression, we compared the transcriptional activity of theC4 genes between high and low C4-producer strains of mice (B10 and FM vs B10.BR) using nuclear transcriptional and chloramphenicol acetyltransferase (CAT) assays. We also compared the level of C4-specific RNA in total and nuclear RNA of the liver. The results revealed no significant difference in transcriptional activity betweenC4 h andC4 l genes. However, the steady-state levels of C4 mRNA are ten times lower inC4 l strains than inC4 h strains, suggesting that the major regulation of C4 plasma levels occurs at the post-transcriptional level.
KeywordsMolecular Mechanism Plasma Level Transcriptional Activity Chloramphenicol Major Regulation
Unable to display preview. Download preview PDF.
- Kioussis, D., Eiferman, F., van de Rijn, P., Gorin, M. B., Ingram, R. S., and Tilgham, S M.: The evolution of α-fetoprotein and albumin. II. The structures of the α-fetoprotein and albumin genes in the mouse.J Biol Chem 256: 1960–1967, 1981Google Scholar
- Marzluff, W. F. and Huang, R. C. C.: Transcription of RNA in isolated nuclei.In B. D. Hames and S. J. Higgins (eds.):Transcription and Translation. A Practical Approach, pp. 89–129, IRL, Eynsham, Oxford, 1984Google Scholar
- Meijlink, F., Curran, T., Miller, A. D., and Verma, I. M.: Removal of a 67-base-pair sequence in the noncoding region of protooncogenefos converts it to a transforming gene.Proc Nod Acad Sci USA 82: 4987–4991, 1985Google Scholar
- Nakayama, K., Nonaka, M., Yokoyama, S., Yu, D.-Y., Pattanakitsakul, S.-N., and Takahashi, M.: Recombination of two homologous MHC class III genes of the mouse (C4 and Slp) that accounts for the loss of testosterone dependence of sex-limited protein expression.J Immunol 138: 620–627, 1987PubMedGoogle Scholar
- Shreffler, D. C.: MHC-linked complement components.In P. Parham and J. Strominger (eds.):Histocompatibility Antigens: Structure and Function, pp. 189–219, Chapman and Hall, London, 1982Google Scholar
- Shreffler, D. C. and Owen, R. D.: A serologically detected variant in mouse serum: inheritance and association with the histocompatibility-2 locus.Genetics 48: 9–25, 1963Google Scholar