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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
SLC35A4 has been classified in the SLC35A subfamily based on amino acid sequence homology. Most of the proteins belonging to the SLC35 family act as transporters of nucleotide sugars. In this study, the subcellular localization of endogenous SLC35A4 was determined via immunofluorescence staining, and it was demonstrated that SLC35A4 localizes mainly to the Golgi apparatus. In silico topology prediction suggests that SLC35A4 has an uneven number of transmembrane domains and its N-terminus is directed towards the Golgi lumen. However, an experimental assay refuted this prediction: SLC35A4 has an even number of transmembrane regions with both termini facing the cytosol. In vivo interaction analysis using the FLIM-FRET approach revealed that SLC35A4 neither forms homomers nor associates with other members of the SLC35A subfamily except
SLC35A5
. Additional assays demonstrated that endogenous SLC35A4 is 10 to 40nm proximal to SLC35A2 and SLC35A3. To determine SLC35A4 function SLC35A4 knock-out cells were generated with the CRISPR-Cas9 approach. Although no significant changes in glycosylation were observed, the introduced mutation influenced the subcellular distribution of the SLC35A2/SLC35A3 complexes. Additional FLIM-FRET experiments revealed that overexpression of SLC35A4-BFP together with SLC35A3 and the SLC35A2-Golgi splice variant negatively affects the interaction between the two latter proteins. The results presented here strongly indicate a modulatory role for SLC35A4 in intracellular trafficking of SLC35A2/SLC35A3 complexes.
Biochim Biophys Acta
Mol
Cell Res 2017 May
PMID:An insight into the orphan nucleotide sugar transporter SLC35A4. 2816 11
Solute carrier family 35 member A5
(
SLC35A5
) is a member of the SLC35A protein subfamily comprising nucleotide sugar transporters. However, the function of
SLC35A5
is yet to be experimentally determined. In this study, we inactivated the
SLC35A5
gene in the HepG2 cell line to study a potential role of this protein in glycosylation. Introduced modification affected neither
N
- nor
O
-glycans. There was also no influence of the gene knock-out on glycolipid synthesis. However, inactivation of the
SLC35A5
gene caused a slight increase in the level of chondroitin sulfate proteoglycans. Moreover, inactivation of the
SLC35A5
gene resulted in the decrease of the uridine diphosphate (UDP)-glucuronic acid, UDP-
N
-acetylglucosamine, and UDP-
N
-acetylgalactosamine Golgi uptake, with no influence on the UDP-galactose transport activity. Further studies demonstrated that
SLC35A5
localized exclusively to the Golgi apparatus. Careful insight into the protein sequence revealed that the C-terminus of this protein is extremely acidic and contains distinctive motifs, namely DXEE, DXD, and DXXD. Our studies show that the C-terminus is directed toward the cytosol. We also demonstrated that
SLC35A5
formed homomers, as well as heteromers with other members of the SLC35A protein subfamily. In conclusion, the
SLC35A5
protein might be a Golgi-resident multiprotein complex member engaged in nucleotide sugar transport.
Int J
Mol
Sci 2019 Jan 11
PMID:SLC35A5 Protein-A Golgi Complex Member with Putative Nucleotide Sugar Transport Activity. 3064 43