Host collaboration : part I

• • • La : binds to 3' end of IRES polio, present all nascent Rnas
    • Poly (rC) binding protein 2 : necessary in entero and rhinovirus
    • Polypyrimidine-tract-binding protein (prb) and heterogeneous nuclear ribonucleoprotein I (hnRNPI) : bind to IRES => negative regulator of alternative pre-mRNA splicing

• => Hypothesis : Tropism of viruses ~ distribution of cellular proteins required for optimal IRES activity