A non-universal transcription factor? The Leishmania tarentolae TATA box-binding protein LtTBP associates with a subset of promoters.
In kinetoplastids a 39-nucleotide spliced leader RNA is trans-spliced to the 5' end of nuclear mRNAs before they can be translated, thus the spliced leader is central to gene expression in kinetoplastid biology. The spliced leader RNA genes in Leishmania tarentolae contain promoters with important sites at approximately -60 and -30. A complex forms specifically on the -60 element as shown by electrophoretic mobility shift. The -60 shift complex has an estimated mass of 159 kDa. An L. tarentolae homologue of TATA-binding protein, LtTBP, co-fractionates with the -60 shift complex. Inclusion of anti-LtTBP antiserum in the shift assay disrupts the shift, indicating that LtTBP is a component of the complex that interacts with the TATA-less -60 element of the spliced leader RNA gene promoter. Both LtTBP and LtSNAP50 are found near the spliced leader RNA gene promoter and the promoters important for tRNAAla and/or U2 snRNA gene transcription, as demonstrated by chromatin immunoprecipitation. The LtTBP appears to interact with a subset of promoters in kinetoplastids with an affinity for short transcription units.
Thomas
Sean
S
Molecular Biology Institute, University of California, Los Angeles, CA 90095-1489, USA.
Yu
Michael C
MC
Sturm
Nancy R
NR
Campbell
David A
DA
D000818:Animals; D001483:Base Sequence; D047369:Chromatin Immunoprecipitation; D002850:Chromatography, Gel; D024202:Electrophoretic Mobility Shift Assay; D007891:Leishmania / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012318:RNA Polymerase I / Q000235:genetics; D012320:RNA Polymerase III / Q000235:genetics; D016053:RNA, Protozoan / Q000032:analysis*; D020038:RNA, Spliced Leader; D035181:TATA-Box Binding Protein / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics
D016053:RNA, Protozoan; D020038:RNA, Spliced Leader; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; D012318:RNA Polymerase I; D012320:RNA Polymerase III