Characteristics of miRNA binding sites in mRNAS of human and mouse titin gene.

We have studied characteristics of miRNA (microRNAs) binding sites in mRNAs (matrix RNAs) of human, primate and mouse titin gene. miRNAs are small non-coding RNAs with the length about 21-22 nucleotides binding with mRNAs of genes and blocking or disturbing their translation. Titin is the largest protein of heart muscle tissue that is a base of myofibril. Defects of titin synthesis lead to malfunction of muscle tissue, for example, to the heart failure which is one of the widest reasons of the death in the world. We have found differences and similarities of characteristics of miRNA binding sites in human and mouse titin gene mRNAs. The differences are the following: different number of binding sites, different values of binding energy and different nucleotide sequences of orthologous human and mouse miRNAs. The similarities are concluded in that all of these sites are located in protein-coding part of mRNA and they all have particular complementarity. But changing some nucleotides can help to get artificial miRNAs with ideal complementarity and maximal effect on expression. We have noticed that characteristics of miRNA binding sites in mRNAs of titin gene between different species of primates are more similar than between human and mouse. It can be explained by different evolutionary distance between these species. So the model of miRNA regulation of mouse titin synthesis is not completely adequate for human titin gene, but weakness of miRNA interaction with mRNA of mouse titin gene can be compensated by increasing of miRNA concentration in relation to mRNA. [ABSTRACT FROM AUTHOR]