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 by C4-high (C4h) or C4-low (C4l) alleles. To investigate the molecular mechanisms underlying the differences in C4 expression, we compared the transcriptional activity of the C4 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 between C4h and C4l genes. However, the steady-state levels of C4 mRNA are ten times lower in C4l strains than in C4h strains, suggesting that the major regulation of C4 plasma levels occurs at the post-transcriptional level.
Nakayama
K
K
Department of Immunobiology, Kanazawa University, Japan.
Pattanakitsakul
S
S
Yokoyama
S
S
Kimura
H
H
Nonaka
M
M
Takahashi
M
M
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002467:Cell Nucleus / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D003181:Complement C4 / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology; D008099:Liver / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D003181:Complement C4; D012333:RNA, Messenger; D015500:Chloramphenicol O-Acetyltransferase