How presence of a signal peptide affects human galectins-1 and -4: Clues to explain common absence of a leader sequence among adhesion/growth-regulatory galectins.
Biochim Biophys Acta Gen Subj
; 1864(1): 129449, 2020 01.
Article
em En
| MEDLINE
| ID: mdl-31678146
ABSTRACT
BACKGROUND:
Galectins are multifunctional effectors, which all share absence of a signal sequence. It is not clear why galectins belong to the small set of proteins, which avoid the classical export route.METHODS:
Products of recombinant galectin expression in P.â¯pastoris were analyzed by haemagglutination, gel filtration and electrophoresis and lectin blotting as well as mass spectrometry on the level of tryptic peptides and purified glycopeptides(s). Density gradient centrifugation and confocal laser scanning microscopy facilitated localization in transfected human and rat cells, proliferation assays determined activity as growth mediator.RESULTS:
Directing galectin-1 to the classical secretory pathway in yeast produces N-glycosylated protein that is active. It cofractionates and -localizes with calnexin in human cells, only Gal-4 is secreted. Presence of N-glycan(s) reduces affinity of cell binding and growth regulation by Gal-1.CONCLUSIONS:
Folding and activity of a galectin are maintained in signal-peptide-directed routing, N-glycosylation occurs. This pathway would deplete cytoplasm and nucleus of galectin, presence of N-glycans appears to interfere with lattice formation. GENERALSIGNIFICANCE:
Availability of glycosylated galectins facilitates functional assays to contribute to explain why galectins invariably avoid classical routing for export.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sinais Direcionadores de Proteínas
/
Adesão Celular
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Galectina 1
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Galectina 4
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Biochim Biophys Acta Gen Subj
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Alemanha