Role of the regulatory domain of the EGF-receptor cytoplasmic tail in selective binding of the clathrin-associated complex AP-2

Boll, Werner; Gallusser, Andreas; Kirchhausen, Tomas

doi:10.1016/s0960-9822(95)00233-8

Cited by 67 publications

(73 citation statements)

References 43 publications

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Section: Pka Regulates Egf Receptor Endocytosismentioning

confidence: 99%

“…Ligand binding induces structural changes in the EGFR that presumably expose cryptic codes in its cytosolic domain, favoring interaction with the clathrin-mediated endocytic apparatus (Boll et al, 1995; Nesterov et al, 1995a,b), mainly through its adaptor AP-2 (Cadena et al, 1994;Nesterov et al, 1995a;Sorkin et al, 1996), although AP-2-independent processes have been also invoked (Sorkin and Carpenter, 1993;Nesterov et al, 1995b). In addition, EGFR activation stimulates the endocytic apparatus through tyrosine-phosphorylation of a variety of downstream substrates needed for its efficient recruitment into coated pits (Lamaze and Schmid, 1995).…”

Section: Introductionmentioning

confidence: 99%

“…Whether H89 induces interaction of EGFR with AP-2 is an interesting possibility to explore in future experiments. In certain conditions, this interaction can occur independently of receptor tyrosine phosphorylation levels and ligand binding (Sorkin and Carpenter, 1993;Boll et al, 1995), or might not even be necessary for EGFR endocytosis, as suggested by studies made with mutant receptors lacking AP-2 binding sites (Nesterov et al, 1995b) and with an AP-2 dominant negative 2 subunit responsible for recognizing endocytic codes (Nesterov et al, 1999).The fate of internalized EGFR under the effect of H89 was different from that seen in cells stimulated with EGF. It was not substantially delivered to a proteasomal-lysosomal pathway as indicated by a lack of degradation during 4 h of H89 treatment and an extensive colocalization with Tf-TxR seen first in peripheral endocytic compartments and then in a punctate juxtanuclear region with the characteristic pattern of recycling endosomes.…”

mentioning

confidence: 98%

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Novel Mechanism for Regulation of Epidermal Growth Factor Receptor Endocytosis Revealed by Protein Kinase A Inhibition

Salazar

González

2002

MBoC

111

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Current models put forward that the epidermal growth factor receptor (EGFR) is efficiently internalized via clathrin-coated pits only in response to ligand-induced activation of its intrinsic tyrosine kinase and is subsequently directed into a lysosomal-proteasomal degradation pathway by mechanisms that include receptor tyrosine phosphorylation and ubiquitylation. Herein, we report a novel mechanism of EGFR internalization that does not require ligand binding, receptor kinase activity, or ubiquitylation and does not direct the receptor into a degradative pathway. Inhibition of basal protein kinase A (PKA) activity by H89 and the cell-permeable substrate peptide Myr-PKI induced internalization of 40 -60% unoccupied, inactive EGFR, and its accumulation into early endosomes without affecting endocytosis of transferrin and -opioid receptors. This effect was abrogated by interfering with clathrin function. Thus, the predominant distribution of inactive EGFR at the plasma membrane is not simply by default but involves a PKA-dependent restrictive condition resulting in receptor avoidance of endocytosis until it is stimulated by ligand. Furthermore, PKA inhibition may contribute to ligand-induced EGFR endocytosis because epidermal growth factor inhibited 26% of PKA basal activity. On the other hand, H89 did not alter ligand-induced internalization of EGFR but doubled its half-time of down-regulation by retarding its segregation into degradative compartments, seemingly due to a delay in the receptor tyrosine phosphorylation and ubiquitylation. Our results reveal that PKA basal activity controls EGFR function at two levels: 1) residence time of inactive EGFR at the cell surface by a process of "endocytic evasion," modulating the accessibility of receptors to stimuli; and 2) sorting events leading to the down-regulation pathway of ligand-activated EGFR, determining the length of its intracellular signaling. They add a new dimension to the fine-tuning of EGFR function in response to cellular demands and cross talk with other signaling receptors. INTRODUCTIONThe mechanisms that regulate the endocytic behavior of epidermal growth factor receptor (EGFR) have been a longstanding subject of intense research as a model system of regulated vesicular protein traffic associated to signaling, cellular demands, and cancer (Trowbridge et al., 1993;Di Fiore and Gill, 1999;Carpenter, 2000;Ceresa and Schmid, 2000;Schlessinger, 2000;Wiley and Burke, 2001). Endocytosis provides a pathway for gradual attenuation or desensitization of receptor signaling and also allows a single receptor to transmit different signals from different locations in the cell before degradation, thus enhancing the range of modulation and response variability (Di Fiore and Gill, 1999;Ceresa and Schmid, 2000;Wiley and Burke, 2001). Defects in internalization and/or degradation pathways, as well as distinct endocytic routing displayed by different EGFR family members, have been associated with cell transformation and oncogenesis (Di Fiore and Gill, 1999;Ceresa and Schm...

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Section: Pka Regulates Egf Receptor Endocytosismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 98%

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Novel Mechanism for Regulation of Epidermal Growth Factor Receptor Endocytosis Revealed by Protein Kinase A Inhibition

Salazar

González

2002

MBoC

111

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“…The cytoplasmic domain sequences are highly conserved for approximately the N-terminal 75% and then diverge. All, however, contain a form of the Tyr-X-X hydrophobic motif, YMPL; this motif has been demonstrated to mediate incorporation into CCVs in mammalian systems [5,6,80,81]. Thus it is likely that all of the members of the VSR family described to date traffic in CCVs.…”

Section: Identification and Cloning Of A Probable Vacuolar Sorting Rementioning

confidence: 99%

Sorting of proteins to vacuoles in plant cells

Neuhaus

Rogers

1998

Protein Trafficking in Plant Cells

132

149

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An individual plant cell may contain at least two functionally and structurally distinct types of vacuoles: protein storage vacuoles and lytic vacuoles. Presumably a cell that stores proteins in vacuoles must maintain these separate compartments to prevent exposure of the storage proteins to an acidified environment with active hydrolytic enzymes where they would be degraded. Thus, the organization of the secretory pathway in plant cells, which includes the vacuoles, has a fascinating complexity not anticipated from the extensive genetic and biochemical studies of the secretory pathway in yeast. Plant cells must generate the membranes to form two separate types of tonoplast, maintain them as separate organelles, and direct soluble proteins from the secretory flow specifically to one or the other via separate vesicular pathways. Individual soluble and membrane proteins must be recognized and sorted into one or the other pathway by distinct, specific mechanisms. Here we review the emerging picture of how separate plant vacuoles are organized structurally and how proteins are recognized and sorted to each type.

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“…Two main classes of endosomal sorting signals have been identified: one class characterized by an essential tyrosine and one by a double leucine (LL) motif or variants thereof (1,2). There is increasing evidence that both classes of sorting signals interact directly with the adaptor complexes AP-1 and AP-2 for clathrindependent sorting from the trans-Golgi network (TGN) 1 or the plasma membrane, respectively (3)(4)(5)(6)(7)(8)(9)(10)(11). Studies on adaptor complexes binding to tail columns indicate a multivalent attachment of aggregated complexes with a binding constant in the micromolar range (3,4,7).…”

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confidence: 99%

A Region from the Medium Chain Adaptor Subunit (μ) Recognizes Leucine- and Tyrosine-based Sorting Signals

Bremnes¹,

Lauvrak²,

Lindqvist³

et al. 1998

Journal of Biological Chemistry

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Tyrosine-based sorting signals in the cytosolic tails of membrane proteins have been found to bind directly to the medium chain subunit () of the adaptor complexes AP-1 and AP-2. For the leucine-based signals, an interaction with AP-1 and AP-2 has been reported, but no specific interacting subunit has been demonstrated. After searching for molecules interacting with the leucinebased sorting signals within the cytosolic tail of the major histocompatibility complex class II-associated invariant chain using a phage display approach, we identified phage clones with homology to a conserved region of the AP-1 and AP-2 chains. To investigate the relevance of these findings, we have expressed regions of mouse 1 and 2 chains on phage gene product III and investigated the binding to tail sequences from various transmembrane proteins with known endosomal targeting signals. Enzyme-linked immunosorbent binding assays showed that these phages specifically recognized peptides containing functional leucine-and tyrosinebased sorting signals, suggesting that these regions of the 1 and 2 chains interact with both types of sorting signals.The cytosolic tails of membrane proteins contain the information for targeting to various intracellular destinations. Two main classes of endosomal sorting signals have been identified: one class characterized by an essential tyrosine and one by a double leucine (LL) motif or variants thereof (1, 2). There is increasing evidence that both classes of sorting signals interact directly with the adaptor complexes AP-1 and AP-2 for clathrindependent sorting from the trans-Golgi network (TGN) 1 or the plasma membrane, respectively (3-11). Studies on adaptor complexes binding to tail columns indicate a multivalent attachment of aggregated complexes with a binding constant in the micromolar range (3, 4,7). This is confirmed by recent data obtained by surface plasmon resonance (9), suggesting a model where binding to the signals is associated with clustering of the adaptors. In fact, adaptor complexes tend to aggregate and drive the formation of coats in vitro (12), and a requirement for AP clustering is in agreement with the current model where adaptors are first recruited to the membrane by a docking protein and then associate to form a coat to where the membrane proteins diffuse laterally.A specific interacting subunit of the AP complexes was recently demonstrated for the tyrosine-based signals as they were shown to interact with both 1 and 2 , the medium chain subunits of AP-1 and AP-2, respectively (10, 13). No such interaction was demonstrated for the leucine class signals in those assays, although there are data indicating that these also mediate binding to the AP complexes (9).The latest information about how signals may be recognized by the sorting machinery was obtained using the yeast twohybrid system (13), a library-based method for studying protein-protein interactions. We have used phage display technology as an alternative library-based approach to obtain more information about protein seque...

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Role of the regulatory domain of the EGF-receptor cytoplasmic tail in selective binding of the clathrin-associated complex AP-2

Cited by 67 publications

References 43 publications

Novel Mechanism for Regulation of Epidermal Growth Factor Receptor Endocytosis Revealed by Protein Kinase A Inhibition

Novel Mechanism for Regulation of Epidermal Growth Factor Receptor Endocytosis Revealed by Protein Kinase A Inhibition

Sorting of proteins to vacuoles in plant cells

A Region from the Medium Chain Adaptor Subunit (μ) Recognizes Leucine- and Tyrosine-based Sorting Signals

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