In vivo evidence for GDP-fucose transport in the absence of transporter SLC35C1 and putative transporter SLC35C2.
J Biol Chem
; 299(12): 105406, 2023 12.
Article
em En
| MEDLINE
| ID: mdl-38270391
ABSTRACT
Slc35c1 encodes an antiporter that transports GDP-fucose into the Golgi and returns GMP to the cytoplasm. The closely related gene Slc35c2 encodes a putative GDP-fucose transporter and promotes Notch fucosylation and Notch signaling in cultured cells. Here, we show that HEK293T cells lacking SLC35C1 transferred reduced amounts of O-fucose to secreted epidermal growth factor-like repeats from NOTCH1 or secreted thrombospondin type I repeats from thrombospondin 1. However, cells lacking SLC35C2 did not exhibit reduced fucosylation of these epidermal growth factor-like repeats or thrombospondin type I repeats. To investigate SLC35C2 functions in vivo, WW6 embryonic stem cells were targeted for Slc35c2. Slc35c2[-/-] mice were viable and fertile and exhibited no evidence of defective Notch signaling during skeletal or T cell development. By contrast, mice with inactivated Slc35c1 exhibited perinatal lethality and marked skeletal defects in late embryogenesis, typical of defective Notch signaling. Compound Slc35c1[-/-]Slc35c2[-/-] mutants were indistinguishable in skeletal phenotype from Slc35c1[-/-] embryos and neonates. Double mutants did not exhibit the exacerbated skeletal defects predicted if SLC35C2 was functionally important for Notch signaling in vivo. In addition, NOTCH1 immunoprecipitated from Slc35c1[-/-]Slc35c2[-/-] neonatal lung carried fucose detected by binding of Aleuria aurantia lectin. Given that the absence of both SLC35C1, a known GDP-fucose transporter, and SLC35C2, a putative GDP-fucose transporter, did not lead to afucosylated NOTCH1 nor to the severe Notch signaling defects and embryonic lethality expected if all GDP-fucose transport were abrogated, at least one more mechanism of GDP-fucose transport into the secretory pathway must exist in mammals.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte de Monossacarídeos
/
Proteínas de Transporte de Nucleotídeos
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Fucose
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
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Pregnancy
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos