Trypanosome spliced leader RNA genes contain the first identified RNA polymerase II gene promoter in these organisms

被引:97
作者
Gilinger, G [1 ]
Bellofatto, V [1 ]
机构
[1] Univ Med & Dent New Jersey, New Jersey Med Sch, Dept Microbiol & Mol Genet, Newark, NJ 07103 USA
关键词
D O I
10.1093/nar/29.7.1556
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Typical general transcription factors, such as TATA binding protein and TFII B, have not yet been identified in any member of the Trypanosomatidae family of parasitic protozoa, Interestingly, mRNA coding genes do not appear to have discrete transcriptional start sites, although in most cases they require an RNA polymerase that has the biochemical properties of eukaryotic RNA polymerase II. A discrete transcription initiation site may not be necessary for mRNA synthesis since the sequences upstream of each transcribed coding region are trimmed from the nascent transcript when a short m(7)G-capped RNA is added during mRNA maturation. This short 39 nt m7G-capped RNA, the spliced leader (SL) sequence, is expressed as an similar to 100 nt long RNA from a set of reiterated, though independently transcribed, genes in the trypanosome genome. Punctuation of the 5' end of mRNAs by a m(7)G cap-containing spliced leader is a developing theme in the lower eukaryotic world; organisms as diverse as Euglena and nematode worms, including Caenorhabditis elegans, utilize SL RNA in their mRNA maturation programs. Towards understanding the coordination of SL RNA and mRNA expression in trypanosomes, we have begun by characterizing SL RNA gene expression in the model trypanosome Leptomonas seymouri, Using a homologous in vitro transcription system, we demonstrate in this study that the SL RNA is transcribed by RNA polymerase II, During SL RNA transcription, accurate initiation is determined by an initiator element with a loose consensus of CYAC/AYR(+1). This element, as well as two additional basal promoter elements, is divergent in sequence from the basal transcription elements seen in other eukaryotic gene promoters. We show here that the in vitro transcription extract contains a binding activity that is specific for the initiator element and thus may participate in recruiting RNA polymerase II to the SL RNA gene promoter.
引用
收藏
页码:1556 / 1564
页数:9
相关论文
共 67 条
[21]   The Leishmania major RNA polymerase II largest subunit lacks a carboxy-terminus heptad repeat structure and its encoding gene is linked with the calreticulin gene [J].
Croan, DG ;
Ellis, J .
PROTIST, 2000, 151 (01) :57-68
[22]   UNUSUAL C-TERMINAL DOMAIN OF THE LARGEST SUBUNIT OF RNA POLYMERASE-II OF CRITHIDIA-FASCICULATA [J].
EVERS, R ;
HAMMER, A ;
CORNELISSEN, AWCA .
NUCLEIC ACIDS RESEARCH, 1989, 17 (09) :3403-3413
[23]   TRYPANOSOMA BRUCEI CONTAINS 2 RNA POLYMERASE-II LARGEST SUBUNIT GENES WITH AN ALTERED C-TERMINAL DOMAIN [J].
EVERS, R ;
HAMMER, A ;
KOCK, J ;
JESS, W ;
BORST, P ;
MEMET, S ;
CORNELISSEN, AWCA .
CELL, 1989, 56 (04) :585-597
[24]   RNA-POLYMERASE III-MEDIATED TRANSCRIPTION OF THE TRYPANOSOME U2 SMALL NUCLEAR-RNA GENE IS CONTROLLED BY BOTH INTRAGENIC AND EXTRAGENIC REGULATORY ELEMENTS [J].
FANTONI, A ;
DARE, AO ;
TSCHUDI, C .
MOLECULAR AND CELLULAR BIOLOGY, 1994, 14 (03) :2021-2028
[25]  
GOLDRING A, 1995, EXPT PARASITOLOGY, V80, P333
[26]   ALPHA-AMANITIN-RESISTANT D-MELANOGASTER WITH AN ALTERED RNA POLYMERASE-II [J].
GREENLEAF, AL ;
BORSETT, LM ;
JIAMACHELLO, PF ;
COULTER, DE .
CELL, 1979, 18 (03) :613-622
[27]   GENETIC AND BIOCHEMICAL-CHARACTERIZATION OF MUTANTS AT AN RNA POLYMERASE-II LOCUS IN DROSOPHILA-MELANOGASTER [J].
GREENLEAF, AL ;
WEEKS, JR ;
VOELKER, RA ;
OHNISHI, S ;
DICKSON, B .
CELL, 1980, 21 (03) :785-792
[28]   CHARACTERIZATION OF THE RNA-POLYMERASES OF TRYPANOSOMA-BRUCEI - TRYPANOSOMAL MESSENGER-RNAS ARE COMPOSED OF TRANSCRIPTS DERIVED FROM BOTH RNA POLYMERASE-II AND POLYMERASE-III [J].
GRONDAL, EJM ;
EVERS, R ;
KOSUBEK, K ;
CORNELISSEN, AWCA .
EMBO JOURNAL, 1989, 8 (11) :3383-3389
[29]   Transcription of the Trypanosoma brucei spliced leader RNA gene is dependent only on the presence of upstream regulatory elements [J].
Gunzl, A ;
Ullu, E ;
Dorner, M ;
Fragoso, SP ;
Hoffmann, KF ;
Milner, JD ;
Morita, Y ;
Nguu, EK ;
Vanacova, S ;
Wunsch, S ;
Dare, AO ;
Kwon, H ;
Tschudi, C .
MOLECULAR AND BIOCHEMICAL PARASITOLOGY, 1997, 85 (01) :67-76
[30]   ESSENTIAL COMPONENTS OF THE MINI-EXON GENE PROMOTER IN THE TRYPANOSOMATID LEPTOMONAS-SEYMOURI [J].
HARTREE, D ;
BELLOFATTO, V .
MOLECULAR AND BIOCHEMICAL PARASITOLOGY, 1995, 71 (01) :27-39