Protein targeting or protein sorting is the biological mechanism by which proteins are transported to their appropriate destinations within or outside the cell. Proteins can be targeted to the inner space of an organelle, different intracellular membranes, the plasma membrane, or to the exterior of the cell via secretion. Information contained in the protein itself directs this delivery process. Correct sorting is crucial for the cell; errors or dysfunction in sorting have been linked to multiple diseases.
The TIM/TOM complex is a protein complex in cellular biochemistry which translocates proteins produced from nuclear DNA through the mitochondrial membrane for use in oxidative phosphorylation. In enzymology, the complex is described as an mitochondrial protein-transporting ATPase, or more systematically ATP phosphohydrolase , as the TIM part requires ATP hydrolysis to work.
Mitochondrial membrane transport proteins, also known as mitochondrial carrier proteins, are proteins which exist in the membranes of mitochondria. They serve to transport molecules and other factors, such as ions, into or out of the organelles. Mitochondria contain both an inner and outer membrane, separated by the inter-membrane space, or inner boundary membrane. The outer membrane is porous, whereas the inner membrane restricts the movement of all molecules. The two membranes also vary in membrane potential and pH. These factors play a role in the function of mitochondrial membrane transport proteins. There are 53 discovered human mitochondrial membrane transporters, with many others that are known to still need discovered.
Mitochondrial import receptor subunit TOM20 homolog is a protein that in humans is encoded by the TOMM20 gene. TOM20 is one of the receptor systems of the translocase of the outer membrane (TOM) complex in the outer mitochondrial membrane.
Mitochondrial import receptor subunit TOM22 homolog(hTom22) is a protein that in humans is encoded by the TOMM22 gene.
Mitochondrial import receptor subunit TOM34 is a protein that in humans is encoded by the TOMM34 gene.
Protein transport protein Sec61 subunit alpha isoform 1 is a protein that in humans is encoded by the SEC61A1 gene.
The translocase of the outer membrane (TOM) is a complex of proteins found in the outer mitochondrial membrane of the mitochondria. It allows movement of proteins through this barrier and into the intermembrane space of the mitochondrion. Most of the proteins needed for mitochondrial function are encoded by the nucleus of the cell. The outer membrane of the mitochondrion is impermeable to large molecules greater than 5000 daltons. The TOM works in conjunction with the translocase of the inner membrane (TIM) to translocate proteins into the mitochondrion. Many of the proteins in the TOM complex, such as TOMM22, were first identified in Neurospora crassa and Saccharomyces cerevisiae. Many of the genes encoding these proteins are designated as TOMM (translocase of the outer mitochondrial membrane) complex genes.
Mitochondrial import inner membrane translocase subunit Tim10 is an enzyme that in humans is encoded by the TIMM10 gene.
Metaxin 1, also known as MTX1, is a protein which in humans is encoded by the MTX1 gene.
28S ribosomal protein S22, mitochondrial is a protein that in humans is encoded by the MRPS22 gene.
Mitochondrial import inner membrane translocase subunit TIM44 is an enzyme that in humans is encoded by the TIMM44 gene.
Mitochondrial import inner membrane translocase subunit Tim9 B is an enzyme that in humans is encoded by the FXC1 gene.
Mitochondrial import inner membrane translocase subunit Tim23 is an enzyme that in humans is encoded by the TIMM23 gene.
Mitochondrial import inner membrane translocase subunit Tim17-A is an enzyme that in humans is encoded by the TIMM17A gene.
Mitochondrial import receptor subunit TOM40 homolog is a protein which in humans is encoded by the TOMM40 gene.
Mitochondrial import inner membrane translocase subunit Tim9 is an enzyme that in humans is encoded by the TIMM9 gene.
Mitochondrial import inner membrane translocase subunit Tim22 is an enzyme that in humans is encoded by the TIMM22 gene.
The translocase of the inner membrane (TIM) is a complex of proteins found in the inner membrane of the mitochondrion. Components of the TIM complex facilitate the translocation of proteins across the inner membrane and into the mitochondrial matrix. They also facilitate the insertion of proteins into the inner mitochondrial membrane, where they must reside in order to function, these mainly include members of the mitochondrial carrier family of proteins.
ADP/ATP translocase 3, also known as solute carrier family 25 member 6, is a protein that in humans is encoded by the SLC25A6 gene.
