Reference - Detail
|Author||Osada Y, Suzuki T, Mizuta H, Mori K, Miura K, Dohmae N, Simizu S.|
|Title||The fibrinogen C-terminal domain is seldom C-mannosylated but its C-mannosylation is important for the secretion of microfibril-associated glycoprotein 4.|
|Journal||Biochim Biophys Acta Gen Subj|
BACKGROUND:C-mannosylation is the one of glycosylations. Microfibril-associated glycoprotein 4 (MFAP4), an important protein for tissue homeostasis and cell adhesion, contains a consensus sequence of C-mannosylation in its fibrinogen C-terminal domain. In this study, we sought to demonstrate that fibrinogen C-terminal domain is a new substrate domain for C-mannosylation.
METHODS:We established an MFAP4-overexpresssing HT1080 cell line and purified recombinant MFAP4 protein from the conditioned medium for LC-MS/MS analysis. Subcellular localization of MFAP4 was observed under confocal fluorescence microscope.
RESULTS:We found that MFAP4 is C-mannosylated at Trp235 in the fibrinogen C-terminal domain by LC-MS/MS. To determine the functions of the C-mannosylation of MFAP4, we established a C-mannosylation-defective mutant MFAP4-overexpresssing HT1080 cell line and measured its secretion of MFAP4. The secretion of MFAP4 decreased significantly in the C-mannosylation-defective mutant MFAP4-overexpresssing cell line versus wild-type cells. Moreover, co-transfection experiments indicated that C-mannosylated MFAP4 accelerated its secretion.
CONCLUSIONS:Our results demonstrate that the fibrinogen C-terminal domain is a novel C-mannosylation domain and that the C-mannosylation of MFAP4 is important for its secretion.
GENERAL SIGNIFICANCE:These results suggest that C-mannosylation has a role for dominant effect for MFAP4 secretion.
|DNA material||Genome Net Work Project Human cDNA clone IRAK141E15 (HGX056511) pCI-neo MFAP4-MH wt (RDB18691) pCI-neo MFAP4-HA WF (RDB18692)|