The dynamic state of liver gap junctions.
By the use of a simple, rapid method for the isolation of gap junctions from small amounts of rat liver (2-3 g), we have followed the incorporation of the radiolabeled amino acid precursors 3H-leucine and 35S-methionine into the gap junction protein. In timed studies with 35S-methionine as precursor, the specific activity in the protein is maximal by 4 h after a single injection of 300 microCi/100 g body weight. From the decay in the specific activity with time after a single injection, the gap junction protein has an apparent half-life of about 19 h. Because of problems of reutilization of radiolabeled amino acid with 35S-methionine as precursor, this apparent half-life probably overestimates the true half-life and indicates a surprisingly rapid turnover of the gap junction protein. This short half-life suggests that, in rat liver, the gap junctions may be very responsive to alterations in physiological demands.
D000818:Animals; D002458:Cell Fractionation; D017630:Connexins; D006207:Half-Life; D007365:Intercellular Junctions / Q000648:ultrastructure*; D007700:Kinetics; D008099:Liver / Q000648:ultrastructure*; D008565:Membrane Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains
D017630:Connexins; D008565:Membrane Proteins; D010446:Peptide Fragments