Differential shedding of the two subunits of the interleukin-6 receptor.
cDNAs coding for the two receptor subunits of the interleukin-6 receptor have been stably expressed in Madine Darby canine kidney (MDCK) cells. The fate of the IL-6 binding protein (IL-6R) and of the signal transducing protein gp130 was studied independently. Both proteins were proteolytically cleaved from cells metabolically labeled with [35S]methionine/cysteine leading to the release of soluble receptor proteins of 55 kDa and 100 kDa, respectively. In contrast to the shedding of the IL-6R gp130 was inefficiently released from the cells and the process was not significantly stimulated by the phorbolester PMA. In addition we show that the soluble forms of the IL-6R and gp130 released by transfected cells can form a ternary complex with interleukin-6 indicating that such complexes also may occur in vivo.
Müllberg
J
J
Institut für Biochemie, RWTH Aachen, Klinikum, Germany.
Dittrich
E
E
Graeve
L
L
Gerhartz
C
C
Yasukawa
K
K
Taga
T
T
Kishimoto
T
T
Heinrich
P C
PC
Rose-John
S
S
D000818:Animals; D015703:Antigens, CD; D002478:Cells, Cultured; D050822:Cytokine Receptor gp130; D004285:Dogs; D008562:Membrane Glycoproteins / Q000378:metabolism; D011233:Precipitin Tests; D018123:Receptors, Interleukin / Q000187:drug effects / Q000378:metabolism*; D019947:Receptors, Interleukin-6; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015703:Antigens, CD; D008562:Membrane Glycoproteins; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130; D013755:Tetradecanoylphorbol Acetate