Algorithm for detecting components of ribonucleoprotein complexes

Proteini so pomembni akterji v mnogih celičnih procesih. Interakcije proteinov in RNA imajo pomembno vlogo pri uravnavanju izražanja genov in posledično njihove funkcije. V interakcijo z RNA navadno vstopa več tako posameznih proteinov kakor tudi skupin proteinov. Metoda iCLIP omogoča do nukleotida natančno detekcijo mest interakcij na RNA z izbranim proteinom. V diplomskem delu smo razvili metodo, ki sprejme nabor mest na RNA, ki so v interakciji z izbranim proteinskim kompleksom. V okolici teh mest nato poišče vzorce interakcij iz nabora interakcij proteinov z RNA, za katere imamo podatke. Najdeni vzorci vključujejo tako posamezne komponente (proteine) danega kompleksa kakor tudi proteine, ki danega kompleksa ne tvorijo, ampak vseeno vplivajo na interakcije kompleksa z RNA. Razvita metoda temelji na postopeku faktorizacije nenegativnih matrik. Metodo smo uspešno preizkusili na podatkih o kompleksu SmB, kjer smo uspešno določiti nekaj proteinov, ki so soudeleženi v kompleksu SmB.Proteins play an important role in many processes in a cell. Protein-RNA interactions greatly affect the balancing of gene expressions and consequently their functions. Interaction with RNA may occur with a single protein or a protein complex. iCLIP method is able to detect the protein-RNA crosslink spots with nucleotide resolution. We developed a method that takes a set of crosslink spots that intersect with the choosen protein complex as an input. Method is searching the crosslink spots neighbourhood for the protein-RNA interaction patterns. Found patterns include parts (proteins) of the choosen complex and other proteins that are not a part of the choosen complex, but still affect the interactions of the choosen complex with the RNA. Method that we developed is based on the non-negative matrix factorization. We successfully tested the method on a SmB complex where we found a few proteins that cooporate with SmB complex