Identification of RNA sequences and structures involved in site-specific cleavage of IGF-II mRNAs.
Insulin-like growth factor-II (IGF-II) mRNAs are subject to site-specific endonucleolytic cleavage in the 3' untranslated region (UTR), rendering an unstable 5' cleavage product containing the coding region and a very stable 3' cleavage product of 1.8 kb consisting of the 3'-UTR sequence and the poly(A) tail. Previously, it was established that two widely separated elements in the 3'-UTR (elements I and II), that can form a duplex structure, are necessary and sufficient for cleavage. To further investigate the sequence and secondary structure requirements for cleavage, we have introduced a number of mutations around the cleavage site and assayed their effects on cleavage. Several recognition determinants involved in the endonucleolytic cleavage of IGF-II mRNAs were identified. Mutational analysis around the cleavage site revealed that cleavage is sequence specific and that the cleavage site must be in a single-stranded conformation to allow efficient cleavage. In addition, we have identified an accessory protein that specifically interacts with a stem-loop structure located 133 to 73 nt upstream of the cleavage site.
van Dijk
E L
EL
Laboratory for Physiological Chemistry, Utrecht University, The Netherlands. E.L.vanDijk@med.uu.nl
Sussenbach
J S
JS
Holthuizen
P E
PE
D020413:3' Untranslated Regions; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D006801:Humans; D006868:Hydrolysis; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism
D020413:3' Untranslated Regions; D017931:DNA Primers; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D007335:Insulin-Like Growth Factor II