Journal article
The Neural Cell Adhesion Molecule Expresses a Tyrosine-independent Basolateral Sorting Signal
The Journal of biological chemistry, Vol.272(7), pp.4559-4567
02/14/1997
DOI: 10.1074/jbc.272.7.4559
PMID: 9020183
Abstract
Transmembrane isoforms of the neural cell adhesion molecule, N-CAM (N-CAM-140 and N-CAM-180), are vectorially targeted from the trans-Golgi network to the basolateral domain upon expression in transfected Madin-Darby canine kidney cells (Powell, S. K., Cunningham, B. A., Edelman, G. M., and Rodriguez-Boulan, E. (1991) Nature 353, 76-77). To localize basolateral targeting information, mutant forms of N-CAM-140 were constructed and their surface distribution analyzed in Madin-Darby canine kidney cells. N-CAM-140 deleted of its cytoplasmic domain shows a non-polar steady state distribution, resulting from delivery from the trans-Golgi network to both the apical and basolateral surfaces. This result suggests that entrance into the basolateral pathway may occur without cytoplasmic signals, implying that apical targeting from the trans-Golgi network is not a default mechanism but, rather, requires positive sorting information. Subsequent construction and analysis of a nested set of C-terminal deletion mutants identified a region of 40 amino acids (amino acids 749-788) lacking tyrosine residues required for basolateral targeting. Addition of these 40 amino acids is sufficient to restore basolateral targeting to both the non-polar cytoplasmic deletion mutant of N-CAM as well as to the apically expressed cytoplasmic deletion mutant of the p75 low affinity neurotrophin receptor (p75(NTR)), indicating that this tyrosine-free sequence is capable of functioning independently as a basolateral sorting signal. Deletion of both cytoplasmic and transmembrane domains resulted in apical secretion of N-CAM, demonstrating that the ectodomain of this molecule carries recessive apical sorting information.
Details
- Title: Subtitle
- The Neural Cell Adhesion Molecule Expresses a Tyrosine-independent Basolateral Sorting Signal
- Creators
- Annick H Le GallSharon K PowellCharles A YeamanEnrique Rodriguez-Boulan
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.272(7), pp.4559-4567
- DOI
- 10.1074/jbc.272.7.4559
- PMID
- 9020183
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Language
- English
- Date published
- 02/14/1997
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984025565902771
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