Conserved sequence elements in K promoters from mice and humans: implications for transcriptional regulation and repertoire expression.
Promoter region sequences of human and mouse Igk-V genes were aligned and found to be conserved for about 200-300 base pairs (bp) within subgroups/families. No promoter similarity was found between IGKV promoters from different human subgroups. Related mouse Igk-V gene families were conserved in the promoter region but no similarity was evident when promoters from unrelated Igk-V gene families were compared. Most of the human IGKV promoter subgroups were shown to have mouse counterparts with a similarity region that extended about 150 bp upstream of the translational start codon. All promoters contained an octamer sequence element. The consensus octamer/decamer sequence was favored but only seven residues within the octamer element were strictly conserved. Furthermore, there was also sequence conservation immediately 3' of the octamer where either an A or a G residue was conserved. In addition, other DNA elements were also conserved both within the Igk-V subgroups/families and between mouse and human promoters from related subgroups/families. In several of the subgroups/families an E box of the E2A type was conserved 5' of the octamer and a CCCT element was conserved within the IGKV subgroup II and its related mouse Igk-V families. We conclude from this study that conservation of additional sequence elements besides the octamer is a common feature in Igk-V promoters but that distinct elements are conserved only within a given subgroup/family. Thus, the conservation appears to have operated at the level of function rather than at the level of recognition sequence for defined transcription factors.
Bemark
M
M
Immunology Group, CMB, Lund University, P.O. Box 7031, S-220 07 Lund, Sweden.
Liberg
D
D
Leanderson
T
T
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D016384:Consensus Sequence; D017124:Conserved Sequence; D005803:Genes, Immunoglobulin; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains