Relationship between the transport from isolated nuclei of two abundant cytoplasmic messengers and the source of a messenger RNA transport factor.

Messenger RNA transport from isolated nuclei requires a 35 X 10(3) dalton cytoplasmic protein(s) which is present in both the cytosol and polyribosome fractions. Recombinant DNA probes containing cDNA inserts were used to quantitate the transport of rat liver-specific albumin and male rat liver-specific alpha 2U-globulin messenger RNA (mRNA) from male rat liver nuclei in response to the mRNA transport factors from homologous and heterologous tissues. No mRNA transport occurs in the absence of the transport factor(s). Both messengers are transported proportionately in response to the factor(s) from male or female rat liver cytosol, or from the polyribosomes (messenger ribonucleoprotein) of male or female rat liver, or brain. The transport factor(s) do not, therefore, appear to differentiate between the coding sequences of two unrelated hepatic messenger RNA's.