Premium
UCHL 1 regulates ubiquitination and recycling of the neural cell adhesion molecule NCAM
Author(s) -
Wobst Hilke,
Förster Sarah,
Laurini Christine,
Sekulla Agathe,
Dreiseidler Michael,
Höhfeld Jörg,
Schmitz Brigitte,
Diestel Simone
Publication year - 2012
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.12029
Subject(s) - neural cell adhesion molecule , colocalization , gene isoform , microbiology and biotechnology , ubiquitin , biology , chemistry , cell adhesion , biochemistry , cell , gene
The neural cell adhesion molecule ( NCAM ) is involved in neural development and in plasticity in the adult brain. NCAM 140 and NCAM 180 isoforms are transmembrane proteins with cytoplasmic domains that differ only in an alternatively spliced exon in the NCAM 180 isoform. Both isoforms can interact with several extracellular and cytoplasmic molecules mediating NCAM ‐dependent functions. Most identified intracellular interaction partners bind to both isoforms, NCAM 140 and NCAM 180. To identify further intracellular interaction partners specifically binding to NCAM 180 the cytosolic domain of human NCAM 180 was recombinantly expressed and applied onto a protein macroarray containing the protein library from human fetal brain. We identified the ubiquitin C ‐terminal hydrolase ( UCHL 1) which has been described as a de‐ubiquitinating enzyme as a potential interaction partner of NCAM 180. Since NCAM 180 and NCAM 140 are ubiquitinated, NCAM 140 was included in the subsequent experiments. A partial colocalization of both NCAM isoforms and UCHL 1 was observed in primary neurons and the B35 neuroblastoma cell line. Overexpression of UCHL 1 significantly decreased constitutive ubiquitination of NCAM 180 and NCAM 140 whereas inhibition of endogenous UCHL 1 increased NCAM 's ubiquitination. Furthermore, lysosomal localization of NCAM 180 and NCAM 140 was significantly reduced after overexpression of UCHL 1 consistent with a partial colocalization of internalized NCAM with UCHL 1. These data indicate that UCHL 1 is a novel interaction partner of both NCAM isoforms that regulates their ubiquitination and intracellular trafficking. Structured digital abstractNCAM1 binds to UCHL1 by protein array ( View interaction ) Uchl1 and NCAM180 colocalize by fluorescence microscopy ( View interaction ) Uchl1 and NCAM1 colocalize by fluorescence microscopy ( View interaction ) Uchl1 and NCAM140 colocalize by fluorescence microscopy ( View interaction )