Developmentally regulated transporter in Leishmania is encoded by a family of clustered genes

摘要

We have previously cloned a gene for a developmentally regulated transport protein from the trypanosomatid protozoan Leishmania enriettil. We demonstrate here that this transporter is encoded by a single family of tandemly clustered genes containing approximately 8 copies of the 3.6 kilobase repeat unit. Transcriptional mapping defines a contiguous 3.3 kilobase region of the repeat unit that encodes the mRNA. The 5′ end of the mature mRNA contains the spliced leader or mlni-exon previously identified in kinetoplastid protozoa, while the 3′ ends of the mRNA are heterogeneous in sequence and in location of the polyadenylation site. We have identified genomic restriction fragments that flank the tandem repeat on the 5′ and 3′ sides and which may be linked to sequences required for expression of the gene family. Other species of Leishmanla also contain sequences that hybridize to the cloned L. enriettil gene at high stringency.