Microtubule-associated protein-4 (MAP-4) inhibits microtubule-dependent distribution of mRNA in isolated neonatal cardiocytes.

Objectives: Active mRNA distribution in the form of ribonucleoprotein particles moving along microtubules has been shown in several cell types, but not yet in cardiocytes. This study addresses two hypotheses: 1) a similar mRNA distribution mechanism operates in cardiocytes; 2) decoration of microtubules with microtubule-associated proteins compromises this distribution.

Methods: To visualize ribonucleoproteins in cultured neonatal rat cardiocytes, they were transfected with vectors encoding zipcode binding protein-1 and Staufen fused with GFP.