A protein’s function is a product of its inherent structural and biochemical characteristics. Equally critical to protein function are elements of its cellular environment including localization, organization and dynamics, which regulate the capacity of a protein to encounter substrates in...

Current estimates suggest that 20‑30% of a typical eukaryotic genome encodes proteins that span a membrane, the majority of which are generated at the endoplasmic reticulum (ER). A remarkable proteinaceous complex embedded in the membrane of the ER, termed the ER translocon, is responsible for...

The endoplasmic reticulum (ER) is the exclusive site of secretory and integral membrane protein synthesis. The process of compartmentalizing protein synthesis to the ER occurs through a positive selection mechanism, the signal recognition particle (SRP) pathway. Growing evidence indicates the ER...

Protein transport into the endoplasmic reticulum (ER) involves a protein translocase that resides in the ER membrane and is highly conserved between lower and higher eukaryotes. The Sec61 complex forms the central component of this translocase, providing a path for the newly synthesized...

Tail‑anchored (TA) proteins are a heterogeneous group of transmembrane proteins with diverse important functions that share an unusual mechanism of insertion into their target membranes. Indeed, because of the C‑terminal position of their transmembrane domain they do not have a chance to...

Molecular chaperones and their co-chaperones of the endoplasmic reticulum (ER) are crucial for efficient ER‑associated protein biogenesis. The major molecular chaperone of the ER, BiP, is a member of the heat shock protein 70 (Hsp70) family and cooperates with co-chaperones of the Hsp40 family,...

A conserved protein translocation channel is formed by the hetero‑trimeric Sec61 complex in eucaryotes and by SecY complex in archaea and eubacteria. Experimental observations including biochemical, biophysical and electron microscopy studies indicate that oligomers of the hetero‑trimeric...

The transport of proteins across biological membranes is a process fundamental to intracellular protein trafficking and organelle biogenesis. Entry into the eukaryotic secretory pathway is initiated by the translocation of proteins across the membrane of the endoplasmic reticulum (ER). This...

Signal sequences are N‑terminal extensions of newly synthesized secretory and membrane proteins. They are usually 16 to 30 amino acid residues in length and comprised of a hydrophilic, usually positively charged N‑terminal region, a central hydrophobic domain and a C‑terminal region with...