Constitutive internalization and association with adaptor protein-2 of the interleukin-6 signal transducer gp130.
The transmembrane protein gp130 is the common signalling receptor subunit for the interleukin-6 (IL-6)-type cytokines. It has recently been shown that the cytoplasmic domain of gp130 contains a dileucine internalization motif and that endocytosis of gp130 occurs signal-independent. Here, we have studied whether gp130 itself undergoes constitutive internalization or whether its endocytosis is stimulated by formation of the IL-6/IL-6R/gp130 complex. Using two different assays, we found that gp130 is internalized independent from IL-6/IL-6R stimulation. In addition, we show that gp130 is constitutively associated with the cell surface adaptor complex AP-2. Our findings strongly suggest endocytosis of gp130 to be constitutive.
Thiel
S
S
Institut für Biochemie der RWTH Aachen, Germany.
Dahmen
H
H
Martens
A
A
Müller-Newen
G
G
Schaper
F
F
Heinrich
P C
PC
Graeve
L
L
D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D002460:Cell Line; D050822:Cytokine Receptor gp130; D004705:Endocytosis; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding
D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D015703:Antigens, CD; C494199:IL6ST protein, human; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D050822:Cytokine Receptor gp130