title: Distinct differences in the requirements for ribonucleoprotein complex formation on differentially regulated pre-edited mRNAs in Trypanosoma brucei.
abstract: Incubation of synthetic pre-edited mRNAs with extracts of Trypanosoma brucei mitochondria results in a family of specific, stable ribonucleoprotein (RNP) complexes that can be visualized by non-denaturing gel electrophoresis. We compared complexes that form with a substrate corresponding to the ATPase 6 (A6) pre-mRNA 3' region that is edited in both bloodstream and procyclic forms with a substrate corresponding to the 5' end of apocytochrome b (CYb) pre-mRNA that is edited only in procyclic (insect) forms. Four to five complexes are detected with both substrates and are specific since competition with homologous but not heterologous substrates prevents their formation. Formation of the CYb complex, however, is more sensitive to heterologous RNAs. In addition, the A6 substrate is more effective at preventing formation of CYb complexes than the converse. CYb complex formation is also more sensitive to divalent cation and salt concentrations and formation of one A6 component has a temperature optimum of 37 degrees C while that of CYb is 27 degrees C.
authors.affiliation: Department of Microbiology, Michigan State University, East Lansing 48824, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Koslowsky
authors.forename: S M
authors.initials: SM
authors.lastname: Kutas
authors.forename: K
authors.initials: K
authors.lastname: Stuart
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics; D000818:Animals; D001059:Apoproteins / Q000235:genetics; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics; D045303:Cytochromes b; D004591:Electrophoresis, Polyacrylamide Gel; D015636:Magnesium Chloride / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D011189:Potassium Chloride / Q000494:pharmacology; D015800:Protozoan Proteins / Q000378:metabolism; D017393:RNA Editing; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism*; D017394:RNA, Guide, Kinetoplastida / Q000378:metabolism; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D013696:Temperature; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000378:metabolism*
chemical_list: D001059:Apoproteins; D003573:Cytochrome b Group; D015800:Protozoan Proteins; D012322:RNA Precursors; D016053:RNA, Protozoan; D012261:Ribonucleoproteins; D015636:Magnesium Chloride; D011189:Potassium Chloride; D045303:Cytochromes b; D000251:Adenosine Triphosphatases; D017394:RNA, Guide, Kinetoplastida