# C‐mannosylation promotes ADAMTS1 activation and secretion in human testicular germ cell tumor NEC8 cells

## TL;DR

This study shows that C-mannosylation at specific sites in ADAMTS1 is crucial for its function and secretion in testicular germ cells.

## Contribution

The study identifies specific C-mannosylation sites in ADAMTS1 and their functional importance in testicular cells.

## Key findings

- ADAMTS1 is C-mannosylated at Trp562 and Trp565 in NEC8 cells.
- C-mannosylation is essential for ADAMTS1 secretion, processing, and enzymatic activity.
- C-mannosylated ADAMTS1 promotes vasculogenic mimicry, while the defective version does not.

## Abstract

C‐mannosylation is a protein glycosylation that regulates the functions of target proteins. Although it has been reported that a disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1), an important spermatogenesis factor, is C‐mannosylated, the roles of C‐mannosylation in ADAMTS1 in testicular cells are still unclear. In this study, we found that ADAMTS1 is C‐mannosylated at Trp562 and Trp565 in testis germ NEC8 cells. To determine the roles of C‐mannosylation in ADAMTS1, we established cells expressing a C‐mannosylation‐defective ADAMTS1, in which C‐mannosylated tryptophan residues were replaced with phenylalanine residues (ADAMTS1/2WF). Processing and secretion of ADAMTS1/2WF were both inhibited compared to those of wild‐type. Moreover, wild‐type ADAMTS1 degraded aggrecan, whereas ADAMTS1/2WF could not. These results indicate the impact of C‐mannosylation on ADAMTS1 function.

C‐mannosylation is a unique form of protein glycosylation. In this study, we demonstrated that ADAMTS1 is C‐mannosylated at Trp562 and Trp565 in human testicular germ cell tumor NEC8 cells. We found that C‐mannosylation of ADAMTS1 is essential for its secretion, processing, enzymatic activity, and ability to promote vasculogenic mimicry. These findings highlight the critical role of C‐mannosylation in regulating ADAMTS1 function.