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Abstract

Small nucleolar RNAs (snoRNAs) are the best characterized non-coding RNAs transcribed by RNA polymerase II. They are produced as precursors, whose extended 3�?? ends are trimmed exonucleolytically whereas 5�?? ends either undergo combined endo and exonucleolytic processing by Rnt1 and Rat1 respectively or remain unchanged. In the latter case, the m7G cap becomes hypermethylated by Tgs1.cRT-PCRand northern blot analyses suggest that processing of snoRNA 3�?? and 5�?? termini is tightly coupled. Inhibition of 5�?? end maturation in rnt1�? strain cause the accumulation of snoRNA precursors that do not possess mature 3�?? ends but carry polyadenylated extensions. This defect is further increased when components of the capbinding complex (CBC) or methyltransferase Tgs1 are missing. Although we observe an accumulation of pre-snoRNAs in rnt1�?? strain, there are also mature snoRNAs present. These results suggest the existence of an alternative pathway of 5�?? end processing that most likely involves pre-snoRNA cap removal by Dcp1/Dcp2 complex. Interestingly most pre-snoRNAs that accumulates in dcp2�? strains are not cleaved by Rnt1 which was confirmed by 5´ RACE analysis. Obtained data strongly suggest the existence of a quality control mechanism that coordinates 5�?? and 3�?? end processing.

Biography

Zaneta Matuszek is a Graduate student of the College of Inter-faculty Individual Studies in Science and Mathematics at the University of Warsaw (Poland). She is involved in two majors: Biotechnology and Chemistry. Since 2011 she has been working in the Institute of Genetics and Biotechnology, University of Warsaw, in a Professor Kufel�??s lab of RNA metabolism in Eukaryotic cells. She is the Organizer of the International Conference Aspects of Neuroscience held annually in Warsaw. Since January 2014 she has been a leader of her own research project granted by �??GeneracjaPrzysz�?o�?ci�?� Polish Ministry of Science and Higher Education Funding Program.