The endoplasmic reticulum (ER) has a quality-control system for 'proof-reading' newly synthesized proteins, so that only native conformers reach their final destinations. Non-native conformers and incompletely assembled oligomers are retained, and, if misfolded persistently, they are degraded. As a large fraction of ER-synthesized proteins fail to fold and mature properly, ER quality control is important for the fidelity of cellular functions. Here, we discuss recent progress in understanding the conformation-specific sorting of proteins at the level of ER retention and export.

Quality control in the endoplasmic reticulum

https://digital.csic.es/bitstream/10261/170827/4/ProgLipResPostprint.pdf

A global perspective on carotenoids: Metabolism, biotechnology, and benefits for nutrition and health

The fatty acid transport function of fatty acid-binding proteins.

The three-dimensional structure of the complex formed by two plasma proteins, transthyretin and retinol-binding protein, was determined from x-ray diffraction data to a nominal resolution of 3.1 angstroms. One tetramer of transthyretin was bound to two molecules of retinol-binding protein. The two retinol-binding protein molecules established molecular interactions with the same transthyretin dimer, and each also made contacts with one of the other two monomers. Thus, the other two potential binding sites in a transthyretin tetramer were blocked. The amino acid residues of the retinol-binding protein that were involved in the contacts were close to the retinol-binding site.

https://science.sciencemag.org/content/sci/268/5213/1039.full.pdf

Structure of a complex of two plasma proteins: transthyretin and retinol-binding protein.

Structural and functional features of different types of cytoplasmic fatty acid-binding proteins

https://www.jbc.org/content/260/10/6472.full.pdf

Brehon Laurent

Papers

Amino Acid Sequence Homologies between Rabbit, Rat, and Human Serum Retinol-binding Proteins*

Characterization of the rat retinol-binding protein gene and its comparison to the three-dimensional structure of the protein.

Cellular retinoid binding proteins.

Ligand-dependent secretion of rat retinol-binding protein expressed in HeLa cells.