| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 5915696 | Molecular and Biochemical Parasitology | 2011 | 5 Pages |
Previous studies of Brugia malayi promoters have suggested that they are unusual in that they lack the CAAT or TATAA boxes that are often emblematic of eucaryotic core promoter domains. Instead, the region surrounding the spliced leader (SL) addition site appears to function as the core promoter domain in B. malayi. To test the hypothesis that polymorphisms in this SL addition domain are important determinants of promoter activity, a series of domain swap mutants were prepared replacing the SL addition domain of the B. malayi 13Â kDa large subunit ribosomal protein (BmRPL13) with those of other ribosomal protein (RP) promoters exhibiting a wide range of activities. These constructs were then tested for promoter activity in a homologous transient transfection system. On average, polymorphisms in the SL addition domain were found to be responsible for 80% of the variation in promoter activity exhibited by the RP promoters tested. Essentially all of this effect could be attributable to polymorphisms in the 10nt located directly upstream of the SL addition site. A comparison of the sequence of this domain to the promoter activity exhibited by the domain swap mutants suggested that promoter activity was related to the number of T residues present in the coding strand of the upstream domain. Confirming this, mutation of the upstream domain of the promoter of the BmRPS4 gene to a homogeneous stretch of 10 T residues resulted in a significant increase in promoter activity.
Graphical abstractThe role that polymorphisms in the SL domain play promoter activity in B. malayi was determined using domain swap mutants.Download high-res image (45KB)Download full-size imageResearch highlightsⶠThe SL addition domain is an important part of the promoter of B. malayi ribosomal protein (RP) genes. ⶠPolymorphisms in this domain account for 80% of the variation in B. malayi RP promoter activity. ⶠThis is due to polymorphisms localized to the 10nt upstream of the SL addition site. ⶠPromoter activity is roughly proportional to the number of T residues in this 10nt upstream domain.
