Aqueous and micelle-bound structural characterization of the epidermal growth factor receptor juxtamembrane domain containing basolateral sorting motifs.
J Biomol Struct Dyn
; 21(6): 813-26, 2004 Jun.
Article
en En
| MEDLINE
| ID: mdl-15107003
ABSTRACT
The EGF receptor is the prototype for four highly related receptors constituting the ErbB family. The EGF receptor is normally targeted to the basolateral membrane in polarized epithelial cells, where it relays information from underlying tissues. Two basolateral sorting signals have been mapped to the cytoplasmic juxtamembrane region of the receptor, a dominant signal comprised of a polyproline core (667-PXXP) and a preceding basic residue (Arg662), and a consensus leucine-based signal (658-LL) responsible for residual sorting when the 667-PXXP signal is absent or defective. The goal of this study was to define the structure of these signals, and gain some insights into how these structures might be regulated by cellular microenvironment. Structural information was acquired for two peptides corresponding to EGF receptor residues Arg645 and Ala674 in aqueous solution or in the presence of membrane-mimicking dodecylphosphocholine micelles, using a variety of NMR and CD spectroscopic methods. Chemical shift data indicate that the 667-PXXP signal does not bind to the micelles and is in random coil state in both aqueous solution and a micellar environment, raising the possibility that 667-PXXP switches to an ordered structure during interaction with the basolateral sorting machinery. In contrast, the adjacent region including 658-LL does bind to micelles mediated by a highly positively charged region located between Arg645 and Arg656. The micelle-bound region also includes Thr654, a known substrate for PKC. This suggests a distinct mode of regulation for this signal involving membrane association and/or phosphorylation.
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Base de datos:
MEDLINE
Asunto principal:
Conformación Proteica
/
Señales de Clasificación de Proteína
/
Polaridad Celular
/
Receptores ErbB
/
Micelas
Idioma:
En
Revista:
J Biomol Struct Dyn
Año:
2004
Tipo del documento:
Article