Abstract
Bovine pituitary rough microsomes were used to determine the ratio of newly synthesized lutropin (LH) α and β subunits in different physiological states of animals. Proteins synthesized by microsomal runoff are derived from preinitiated mRNAs and thus, in the present case, should reflect the initial intracellular steady state levels of the subunits. The products were identified by immunoprecipitation using bovine LH subunit specific antisera and analyzed by electrophoresis on sodium dodecyl sulfate-polyacrylamide gels. Microsomes isolated from castrated animals (steers) synthesized comparable amounts of LHα- and LHβ-subunits as determined by quantitation of the immunoprecipitated products. However, microsomes from intact animals (bulls) directed the synthesis of 3-5 times more α than LHβ. A comparison of the levels of α- and LHβ-subunits synthesized by an equivalent concentration of bull and steer pituitary microsomes indicates that the increased ratio of α to LHβ in bull pituitary microsomes is the result of a preferential decrease in the synthesis of the LHβ subunit. The results suggest that the rate of β subunit synthesis determines the level of intact LH produced.
Original language | English |
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Pages (from-to) | 8143-8147 |
Number of pages | 5 |
Journal | Journal of Biological Chemistry |
Volume | 257 |
Issue number | 14 |
State | Published - 1982 |