The cell-surface expression and function of multisubunit plasma membrane proteins are regulated via interactions between catalytic subunits and auxiliary subunits. Subunit assembly in the endoplasmic reticulum is required for the cell-surface expression of the enzyme, but little is known about subunit interactions once it reaches the plasma membrane. Here we performed highly quantitative analys...

Sophisticated quality control mechanisms prolong retention of protein-folding intermediates in the endoplasmic reticulum (ER) until maturation while sorting out terminally misfolded polypeptides for ER-associated degradation (ERAD). The presence of structural lesions in the luminal, transmembrane, or cytosolic domains determines the classification of misfolded polypeptides as ERAD-L, -M, or -C ...

Although Fibrobacter succinogenes S85 is one of the most proficient cellulose degrading bacteria among all mesophilic organisms in the rumen of herbivores, the molecular mechanism behind cellulose degradation by this bacterium is not fully elucidated. Previous studies have indicated that cell surface proteins might play a role in adhesion to and subsequent degradation of cellulose in this bacte...

Overactivation of NMDA receptors is believed to induce neuronal death by increasing phospholipid hydrolysis and subsequent degradation. We showed previously that NMDA releases choline and inhibits incorporation of [3H]choline into phosphatidylcholine before excitotoxic neuronal death. On the basis of these results, we hypothesized that excitotoxicity results from inhibition of synthesis rather ...

The second step of dolichol-linked oligosaccharide synthesis in the N-linked glycosylation pathway at the endoplasmic reticulum (ER) membrane is catalyzed by an unusual hetero-oligomeric UDP-N-acetylglucosamine transferase that in most eukaryotes is comprised of at least two subunits, Alg13p and Alg14p. Alg13p is the cytosolic and catalytic subunit that is recruited to the ER by the membrane pr...

The recent wave of interest in sustainability has brought the benefits of fuel cells into the public sphere. Polymer electrolyte membrane fuel cells provide clean and renewable energy, but are subject to degradation. Given the possibilities for use in remote applications, it is necessary to understand and minimize degradation of fuel cell components. Here we analyze common types of degradation ...

Functional and structural studies of membrane proteins usually require overexpression of the proteins in question. Often, however, the 'trial and error' approaches that are mainly used to produce membrane proteins are not successful. Our rapidly increasing understanding of membrane protein insertion, folding and degradation means that membrane protein overexpression can be more rationalized, bo...