Biomaterial Database

Mechanisms of Sec61/SecY-mediated protein translocation across membranes. 2012

Eunyong Park, and Tom A Rapoport

Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.

The Sec61 or SecY channel, a universally conserved protein-conducting channel, translocates proteins across and integrates proteins into the eukaryotic endoplasmic reticulum (ER) membrane and the prokaryotic plasma membrane. Depending on channel-binding partners, polypeptides are moved by different mechanisms. In cotranslational translocation, the ribosome feeds the polypeptide chain directly into the channel. In posttranslational translocation, a ratcheting mechanism is used by the ER-lumenal chaperone BiP in eukaryotes, and a pushing mechanism is utilized by the SecA ATPase in bacteria. In prokaryotes, posttranslational translocation is facilitated through the function of the SecD/F protein. Recent structural and biochemical data show how the channel opens during translocation, translocates soluble proteins, releases hydrophobic segments of membrane proteins into the lipid phase, and maintains the barrier for small molecules.

UI	MeSH Term	Description	Entries
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D011387	Prokaryotic Cells	Cells lacking a nuclear membrane so that the nuclear material is either scattered in the cytoplasm or collected in a nucleoid region.	Cell, Prokaryotic,Cells, Prokaryotic,Prokaryotic Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D000069816	SEC Translocation Channels	Universally conserved multiprotein complexes that form the protein transport channel of the general secretory (SEC) pathway. The SEC translocase is present in all bacteria, archaea, and eukaryotes. It is in the ENDOPLASMIC RETICULUM membrane of eukaryotic cells, in the THYLAKOID MEMBRANE in CHLOROPLASTS and in some protozoa in the INNER MITOCHONDRIAL MEMBRANE.	SEC Translocation Channel,SEC Translocon,SEC61 Translocation Channel,Sec Protein Translocation System,SecYEG Protein,SecYEG Translocation Channel,SEC Complexes,SEC Translocase,SEC Translocons,SEC61 Protein,SEC61 Proteins,SEC61 Translocase,SEC61 Translocation Channels,SEC61 Translocon,Sec Protein Translocation Systems,Sec61 Complex,Sec61 Protein Translocation System,SecY Translocase,SecYEG Complex,SecYEG Complexes,SecYEG Protein Translocation System,SecYEG Proteins,SecYEG Translocation Channels,SecYEG Translocon,Channel, SEC Translocation,Channel, SEC61 Translocation,Channel, SecYEG Translocation,Channels, SEC Translocation,Channels, SEC61 Translocation,Channels, SecYEG Translocation,Complex, Sec61,Complex, SecYEG,Complexes, SEC,Complexes, SecYEG,Protein, SEC61,Protein, SecYEG,Proteins, SEC61,Proteins, SecYEG,Translocase, SEC,Translocase, SEC61,Translocase, SecY,Translocation Channel, SEC,Translocation Channel, SEC61,Translocation Channel, SecYEG,Translocation Channels, SEC,Translocation Channels, SEC61,Translocation Channels, SecYEG,Translocon, SEC,Translocon, SEC61,Translocon, SecYEG,Translocons, SEC
D056890	Eukaryota	One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.	Eukaryotes,Eucarya,Eukarya,Eukaryotas,Eukaryote
D021381	Protein Transport	The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.	Cellular Protein Targeting,Gated Protein Transport,Protein Targeting, Cellular,Protein Translocation,Transmembrane Protein Transport,Vesicular Protein Transport,Protein Localization Processes, Cellular,Protein Sorting,Protein Trafficking,Protein Transport, Gated,Protein Transport, Transmembrane,Protein Transport, Vesicular,Traffickings, Protein