SorLA in Interleukin-6 Signaling and Turnover.
Mol Cell Biol
; 37(11)2017 06 01.
Article
em En
| MEDLINE
| ID: mdl-28265003
ABSTRACT
Interleukin-6 (IL-6) is a multifunctional cytokine with important functions in various physiologic processes. Mice lacking IL-6 exhibit multiple phenotypic abnormalities, such as an inadequate immune and acute-phase response, and elevated levels of circulating IL-6 have been found to accompany several pathological conditions. IL-6 binds the nonsignaling IL-6 receptor (IL-6R), which is expressed as a transmembrane, as well as a secreted circulating protein, before it engages homodimeric gp130 for signaling. Complex formation between IL-6 and the membrane-bound IL-6 receptor gives rise to classic cis signaling, whereas complex formation between IL-6 and the soluble IL-6R results in trans signaling. Here, we report that the endocytic receptor SorLA targets IL-6 and IL-6R. We present evidence that SorLA mediates efficient cellular uptake of both IL-6 and the circulating IL-6R in astrocytes. We further show that SorLA interacts with the membrane-bound IL-6R at the cell surface and thereby downregulates IL-6 cis signaling. Finally, we find that the SorLA ectodomain, released from the cell membrane upon enzymatic cleavage of full-length SorLA, may act as an IL-6 carrier protein that stabilizes IL-6 and its capacity for trans signaling.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Membrana Transportadoras
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Receptores de LDL
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Transdução de Sinais
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Interleucina-6
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Proteínas Relacionadas a Receptor de LDL
Limite:
Animals
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Humans
Idioma:
En
Revista:
Mol Cell Biol
Ano de publicação:
2017
Tipo de documento:
Article