Heterogeneity of alpha 2u-globulin gene products in different translational systems, plasma and urine.

alpha 2u-Globulin, an androgen dependent rat urinary protein, displays considerable microheterogeneity. To explore whether this microheterogeneity of alpha 2u-globulin in male rat urine is related to the heterogeneity at the level of the genes encoding this protein, or whether it is due to post-translational processing we studied the alpha 2u-globulin mRNA translation products in rabbit reticulocyte and Xenopus oocytes. Comparison of the alpha 2u-globulin species produced in these two heterologous systems with those observed in plasma and urine indicates that the heterogeneity of this protein in urine is mainly due to heterogeneity at the level of the corresponding mRNAs.