The Rab family of proteins is a member of the Ras superfamily of small G proteins. Approximately 70 types of Rabs have now been identified in humans. Rab proteins generally possess a GTPase fold, which consists of a six-stranded beta sheet which is flanked by five alpha helices. Rab GTPases regulate many steps of membrane trafficking, including vesicle formation, vesicle movement along actin and tubulin networks, and membrane fusion. These processes make up the route through which cell surface proteins are trafficked from the Golgi to the plasma membrane and are recycled. Surface protein recycling returns proteins to the surface whose function involves carrying another protein or substance inside the cell, such as the transferrin receptor, or serves as a means of regulating the number of a certain type of protein molecules on the surface.
Prenylation is the addition of hydrophobic molecules to a protein or a biomolecule. It is usually assumed that prenyl groups (3-methylbut-2-en-1-yl) facilitate attachment to cell membranes, similar to lipid anchors like the GPI anchor, though direct evidence of this has not been observed. Prenyl groups have been shown to be important for protein–protein binding through specialized prenyl-binding domains.
Choroideremia is a rare, X-linked recessive form of hereditary retinal degeneration that affects roughly 1 in 50,000 males. The disease causes a gradual loss of vision, starting with childhood night blindness, followed by peripheral vision loss and progressing to loss of central vision later in life. Progression continues throughout the individual's life, but both the rate of change and the degree of visual loss are variable among those affected, even within the same family.
Rab escort protein 1 (REP1) also known as rab proteins geranylgeranyltransferase component A 1 is an enzyme that in humans is encoded by the CHM gene.
Melanophilin is a carrier protein which in humans is encoded by the MLPH gene. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined.
Ras-related protein Rab-5A is a protein that in humans is encoded by the RAB5A gene.
Ras-related protein Rab-6A is a protein that in humans is encoded by the RAB6A gene located in the eleventh chromosome. Its main function is the regulation of protein transport from the Golgi complex to the endoplasmic reticulum and the exocytosis along with the microtubules.
Ras-related protein Rab-3A is a protein that in humans is encoded by the RAB3A gene. It is involved in calcium-triggered exocytosis in neurons.
Ras-related protein Rab-1A is a protein that in humans is encoded by the RAB1A gene.
Crumbs homolog 1 is a protein that in humans is encoded by the CRB1 gene.
Gamma-crystallin B is a protein that in humans is encoded by the CRYGB gene.
Ras-related protein Rab-14 is a protein that in humans is encoded by the RAB14 gene.
Ras-related protein Rab-25 is a protein that in humans is encoded by the RAB25 gene. It is thought to act as a promoter of tumor development.
Ras-related protein Rab-21 is a protein that in humans is encoded by the RAB21 gene.
Ras-related protein Rab-39B is a protein that in humans is encoded by the RAB39B gene.
Ras-related protein Rab-40A is a protein that in humans is encoded by the RAB40A gene.
60S ribosomal protein L17 is a protein that in humans is encoded by the RPL17 gene.
Plexin-D1 is a protein that in humans is encoded by the PLXND1 gene.
Ras-related protein Rab-15 is a protein that in humans is encoded by the RAB15 gene.
Ras-related protein Rab-27A is a protein that in humans is encoded by the RAB27A gene.
