Poster Presentation 2014 International Biophysics Congress

Bioinformatics analyses of mRNA cleavage-polyadenylation specificity factor complex toward its structure prediction (#684)

Saki Aoto 1 , Kei Yura 1 2
  1. Ochanomizu University, Tokyo, Japan
  2. National Institute of Genetics, Mishima, Japan
A eukaryotic messenger RNA (mRNA) undergoes a number of maturation processes such as splicing and polyadenylation after transcription. Each of these processes is performed on a large protein complex molecule. Recent studies revealed that mRNAs bind to several different proteins and form different mRNPs. The components of those mRNPs are being identified, but the mechanistic detail of the mRNPs remains to be elucidated. A long polyadenylation of mRNA is a specific process for eukaryotic cells and it is known to contribute to the stability of mRNA. Polyadenylation itself is performed by poly(A) polymerase and its mechanism has been well elucidated, but its initiation process is still unclear. One of the mRNPs involved in the first step of mRNA polyadenylation process is cleavage and polyadenylation specificity factor (CPSF), a hetero-tetramer molecule that binds to the 3'-terminal of mRNA. We analyzed the sequences of each subunit aiming for the prediction of its entire structure and of its role in polyadenylation initiation step. By analyzing the amino acid sequences with molecular phylogenetic method, we found that each subunit of CPSF had paralogues with completely different function. This finding let us extract information of paralogue specific mutations that may contain hints for subunit interaction sites. With three-dimensional structures of each subunit obtained by comparative modeling, the possible entire structure of CPSF was deduced. We mapped the experimentally identified characteristics of CPSF onto the structures and evaluated the accuracy of the structure.