Аннотация: Продолжение серии статей про влияние двуцепочечного концевого стема на время жизни различных малых РНК
A 5′-3′ terminal stem in small non-coding RNAs extends their lifetime
Anastasia P. Koval, Irina K. Gogolevskaya, Karina A. Tatosyan, Dmitri A. Kramerov,
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
Received 12 September 2014, Revised 24 October 2014, Accepted 31 October 2014, Available online 7 November 2014
http://dx.doi.org/10.1016/j.gene.2014.10.061
Abstract
4.5SI and 4.5SH are two non-coding RNAs about 100 nt long, synthesized by RNA polymerase III in cells of various rodents including mice, rats, and hamsters. The first RNA is long-lived whereas the half-life of the second is only 20 min. We previously found that the 16 bp double-stranded structure (stem), formed by 4.5SI RNA termini, contributes essentially to the long lifetime of this RNA (Koval et al., 2012). The rapid decay of 4.5SH RNA seems to be related to the lack of a similar structure in this RNA. The aim of this work was to verify whether the lifetime of any other short-lived non-coding RNA can be prolonged following creation of the double-stranded structure with its terminal regions. Here RNAs transcribed by RNA polymerase III from short interspersed elements (SINEs) B2 and Rhin-1 from the genomes of mouse and horseshoe bat, respectively, were used. Replacement of 16 nt at the 3′-terminal region by the sequence complementary to the 5′ end region of B2 and Rhin-1 RNA increased their half-life more than 4 fold. In addition, we demonstrated that shortening of the terminal stem from 16 to 8 bp decreased only slightly the 4.5SI RNA lifetime. Finally, we showed that the disruption of an internal (non-terminal) stem in 4.5SI RNA did not accelerate its decay in cells. Possible mechanisms of the small non-coding RNA lifetime extension are discussed.