Specific factors are required for kinase-dependent endocytosis of insulin receptors

JB Welsh, R Worthylake, HS Wiley and GN Gill

Department of Pathology, University of California San Diego, La Jolla 92093-0650.

Mouse B82 cells that support high affinity saturable endocytosis of epidermal growth factor receptors (EGFR) exhibited only low rates of nonsaturable internalization of insulin receptors (InsR). To investigate the defect in endocytosis of InsR in B82 cells, we examined the role of sequence motifs and tyrosine kinase, the two receptor components shown to be required for efficient saturable endocytosis of InsR in Rat 1 cells. Placement of residues encoded by exon 16 of the InsR onto an EGFR truncated to residue 958 restored EGF-induced internalization of this mutant receptor indicating that the sequence codes in exon 16 are recognized by B82 cells. To determine whether the kinase function could be provided in trans, a B82 cell expressing both receptors was established. EGF-activated EGFR kinase was not able to restore insulin-dependent rapid endocytosis to InsR. However, fusion of untransfected Rat1 cells with InsR-expressing B82 cells enabled rapid endocytosis of InsR, indicating that the internalization defect can be complemented. These results indicate that, although internalization codes can function in the context of other receptors, activation of tyrosine kinase receptors requires an additional specific component.

Volume 5, Issue 5, pp. 539-547, 05/01/1994
Copyright © 1994 by The American Society for Cell Biology

This article has been cited by other articles:

				W. Wu, L. M. Graves, G. N. Gill, S. J. Parsons, and J. M. Samet Src-dependent Phosphorylation of the Epidermal Growth Factor Receptor on Tyrosine 845 Is Required for Zinc-induced Ras Activation J. Biol. Chem., June 28, 2002; 277(27): 24252 - 24257. [Abstract] [Full Text] [PDF]

				H.-J. S. Huang, M. Nagane, C. K. Klingbeil, H. Lin, R. Nishikawa, X.-D. Ji, C.-M. Huang, G. N. Gill, H. S. Wiley, and W. K. Cavenee The Enhanced Tumorigenic Activity of a Mutant Epidermal Growth Factor Receptor Common in Human Cancers Is Mediated by Threshold Levels of Constitutive Tyrosine Phosphorylation and Unattenuated Signaling J. Biol. Chem., January 31, 1997; 272(5): 2927 - 2935. [Abstract] [Full Text] [PDF]

				P. Formisano, S. M. Najjar, C. N. Gross, N. Philippe, F. Oriente, C. L. Kern-Buell, D. Accili, and P. Gorden Receptor-mediated Internalization of Insulin J. Biol. Chem., October 13, 1995; 270(41): 24073 - 24077. [Abstract] [Full Text] [PDF]

				J.-L. Carpentier and D. McClain Insulin Receptor Kinase Activation Releases a Constraint Maintaining the Receptor on Microvilli J. Biol. Chem., March 10, 1995; 270(10): 5001 - 5006. [Abstract] [Full Text] [PDF]

				L. K. Opresko, C.-P. Chang, B. H. Will, P. M. Burke, G. N. Gill, and H. S. Wiley Endocytosis and Lysosomal Targeting of Epidermal Growth Factor Receptors Are Mediated by Distinct Sequences Independent of the Tyrosine Kinase Domain J. Biol. Chem., March 3, 1995; 270(9): 4325 - 4333. [Abstract] [Full Text] [PDF]