Purified EDEM3 or EDEM1 alone produces determinant oligosaccharide structures from M8B in mammalian glycoprotein ERAD.

Sequential mannose trimming of N-glycan, from M9 to M8B and then to oligosaccharides exposing the α1,6-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 α1,2-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 α1,2-mannosidase is required for gpERAD. Accordingly, we have established the entire route of oligosaccharide processing and the enzymes responsible

Water Quality in the Valparaiso Chain of Lakes Watershed

The water quality in the Valparaiso Chain of Lakes watershed has been regularly monitored for the past decade. Eleven lakes and associated streams, ponds, and wetlands make up the watershed. Multiple tests were performed in the field including measurements of pH, temperature, dissolved oxygen, conductivity, chloride concentration, nitrate concentration, ammonium concentration, and clarity. Samples were collected and an assortment of laboratory tests were also performed including total and reactive phosphorus, biological oxygen demand (BOD), total coliforms and E. coli, and total suspended solids (TSS). Most of the parameters monitored have remained relatively constant in the watershed. One notable exception is that the total and reactive phosphorus levels for most of the lakes tests have generally decreased from their levels at the beginning of research in 2005. Water quality and clarity have also somewhat improved. These improvements are attributed to efforts made by various organizations, groups, and individuals near the watershed to better manage the lakes. By continuing to collaborate and interact with the community, we anticipate growing awareness of the factors affecting water quality in the watershed and that sound management practices will expand and lead to further improvements in the quality of the watershed