Mutational and secondary structural analysis of the basolateral sorting signal of the polymeric immunoglobulin receptor - PubMed (original) (raw)

Comparative Study

Mutational and secondary structural analysis of the basolateral sorting signal of the polymeric immunoglobulin receptor

B Aroeti et al. J Cell Biol. 1993 Dec.

Abstract

The 17-juxtamembrane cytoplasmic residues of the polymeric immunoglobulin receptor contain an autonomous basolateral targeting signal that does not mediate rapid endocytosis (Casanova, J. E., G. Apodaca, and K. E. Mostov. Cell. 66:65-75). Alanine-scanning mutagenesis identifies three residues in this region, His656, Arg657, and Val660, that are most essential for basolateral sorting and two residues, Arg655 and Tyr668, that play a lesser role in this process. Progressive truncations suggested that Ser664 and Ile665 might also play a role in basolateral sorting. However, mutation of these residues to Ala or internal deletions of these residues did not affect basolateral sorting, indicating that these residues are probably not required for basolateral sorting. Two-dimensional NMR spectroscopy of a peptide corresponding to the 17-mer signal indicates that the sequence Arg658-Asn-Val-Asp661 has a propensity to adopt a beta-turn in solution. Residues COOH-terminal to the beta-turn (Arg662 to Arg669) seem to take up a nascent helix structure in solution. Substitution of Val660 with Ala destabilizes the turn, while mutation of Arg657 to Ala does not appear to affect the turn structure. Neither mutation detectably altered the stability of the nascent helix in the COOH-terminal portion of the peptide.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Cell. 1986 Nov 7;47(3):359-64 - PubMed
    1. Methods Cell Biol. 1989;32:329-37 - PubMed
    1. J Cell Biol. 1987 Dec;105(6 Pt 1):2735-43 - PubMed
    1. J Cell Biol. 1990 Oct;111(4):1393-407 - PubMed
    1. Cell. 1991 Dec 20;67(6):1203-9 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources