1. Purified EDEM3 or EDEM1 alone produces determinant oligosaccharide structures from M8B in mammalian glycoprotein ERAD
- Author
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70378529, 70182194, Ginto, George, Ninagawa, Satoshi, Yagi, Hirokazu, Furukawa, Jun-ichi, Hashii, Noritaka, Ishii-Watabe, Akiko, Deng, Ying, Matsushita, Kazutoshi, Ishikawa, Tokiro, Mamahit, Yugoviandi P, Maki, Yuta, Kajihara, Yasuhiro, Kato, Koichi, Okada, Tetsuya, Mori, Kazutoshi, 70378529, 70182194, Ginto, George, Ninagawa, Satoshi, Yagi, Hirokazu, Furukawa, Jun-ichi, Hashii, Noritaka, Ishii-Watabe, Akiko, Deng, Ying, Matsushita, Kazutoshi, Ishikawa, Tokiro, Mamahit, Yugoviandi P, Maki, Yuta, Kajihara, Yasuhiro, Kato, Koichi, Okada, Tetsuya, and Mori, Kazutoshi
- Abstract
Sequential mannose trimming of N-glycan, from M9 to M8B and then to oligosaccharides exposing the a1, 6-linked mannosyl residue (M7A, M6 and M5), facilitates endoplasmic reticulum-associated degradation of misfolded glycoproteins (gpERAD). We previously showed that EDEM2 stably disulfide-bonded to the thioredoxin domain-containing protein TXNDC11 is responsible for the first step (George et al., 2020). Here, we show that EDEM3 and EDEM1 are responsible for the second step. Incubation of pyridylamine-labeled M8B with purified EDEM3 alone produced M7 (M7A and M7C), M6 and M5. EDEM1 showed a similar tendency, although much lower amounts of M6 and M5 were produced. Thus, EDEM3 is a major a1, 2-mannosidase for the second step from M8B. Both EDEM3 and EDEM1 trimmed M8B from a glycoprotein efficiently. Our confirmation of the Golgi localization of MAN1B indicates that no other a1, 2-mannosidase is required for gpERAD. Accordingly, we have established the entire route of oligosaccharide processing and the enzymes responsible.
- Published
- 2021