Hnrnpc binds pre-mRNA and nucleates the assembly of 40S hnRNP particles. Single HNRNPC tetramers bind 230-240 nucleotides. Trimers of HNRNPC tetramers bind 700 nucleotides. Hnrnpc may play a role in the early steps of spliceosome assembly and pre-mRNA splicing. Hnrnpc interacts with poly-U tracts in the 3-UTR or 5-UTR of mRNA and modulates the stability and the level of translation of bound mRNA molecules.