SEQUENCE AND SPATIAL REQUIREMENTS FOR THE TISSUE-INDEPENDENT AND SPECIES-INDEPENDENT 3'-END PROCESSING MECHANISM OF PLANT MESSENGER-RNA

Citation
L. Wu et al., SEQUENCE AND SPATIAL REQUIREMENTS FOR THE TISSUE-INDEPENDENT AND SPECIES-INDEPENDENT 3'-END PROCESSING MECHANISM OF PLANT MESSENGER-RNA, Molecular and cellular biology, 14(10), 1994, pp. 6829-6838
Citations number
35
Categorie Soggetti
Biology
ISSN journal
02707306
Volume
14
Issue
10
Year of publication
1994
Pages
6829 - 6838
Database
ISI
SICI code
0270-7306(1994)14:10<6829:SASRFT>2.0.ZU;2-N
Abstract
Two cis-regulatory regions are required for efficient mRNA 3'-end proc essing of the maize 27-kDa zein mRNA: a region containing a duplicated AAUGAA poly(A) signal and a region that is present upstream from it. Strict spatial positioning of these two regions is required for effici ent mRNA 3'-end processing. Insertion of a stuffer sequence as short a s 17 or 18 bp either between the upstream region and the two AAUGAA mo tifs or between the two AAUGAA motifs drastically reduced the efficien cy of 3'-end processing. Mutational analyses of the nucleotide prefere nce at the fourth position of the AAUGAA motif revealed the preference order G > A >> C or U, suggesting that AAUAAA is neither a defective nor an optimal poly(A) Signal for the 27-kDa zein mRNA. As for the 3' control region of the cauliflower mosaic virus (CaMV) transcription un it, the mRNA 3'-end processing mechanism mediated by the 27-kDa zein 3 ' control sequence is neither tissue nor species specific. The 3' upst ream sequence of the 27-kDa zein gene can functionally replace that of the CaMV transcription unit. Conversely, the CaMV upstream sequence c an mediate mRNA polyadenylation in the presence of a duplicated 27-kDa zein poly(A) signal. However, instead of the proximal poly(A) signal normally used in the 27-kDa zein mRNA, the distal signal is utilized. These results suggest that a general mechanism controls the 3'-end pro cessing of plant mRNAs and that the cia-regulatory functions mediated by their upstream regions are interchangeable.