Ras-related protein Rab-8A is a protein that in humans is encoded by the RAB8A gene. [5] [6] [7]
The protein encoded by this gene is a member of the RAS superfamily which are small GTP/GDP-binding proteins with an average size of 200 amino acids. The RAS-related proteins of the RAB/YPT family may play a role in the transport of proteins from the endoplasmic reticulum to the Golgi and the plasma membrane. This protein shares 97%, 96%, and 51% similarity with the dog RAB8, mouse MEL, and mouse YPT1 proteins, respectively and contains the 4 GTP/GDP-binding sites that are present in all the RAS proteins. The putative effector-binding site of this protein is similar to that of the RAB/YPT proteins. However, this protein contains a C-terminal CAAX motif that is characteristic of many RAS superfamily members but which is not found in YPT1 and the majority of RAB proteins. Although this gene was isolated as a transforming gene from a melanoma cell line, no linkage between MEL and malignant melanoma has been demonstrated. This oncogene is located 800 kb distal to MY09B on chromosome 19p13.1. [7]
RAB8A has been shown to interact with Optineurin [8] and MAP4K2. [9]
GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a protein domain common to many GTPases.
Small GTPases, also known as small G-proteins, are a family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate (GTP). They are a type of G-protein found in the cytosol that are homologous to the alpha subunit of heterotrimeric G-proteins, but unlike the alpha subunit of G proteins, a small GTPase can function independently as a hydrolase enzyme to bind to and hydrolyze a guanosine triphosphate (GTP) to form guanosine diphosphate (GDP). The best-known members are the Ras GTPases and hence they are sometimes called Ras subfamily GTPases.
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.
Transforming protein RhoA, also known as Ras homolog family member A (RhoA), is a small GTPase protein in the Rho family of GTPases that in humans is encoded by the RHOA gene. While the effects of RhoA activity are not all well known, it is primarily associated with cytoskeleton regulation, mostly actin stress fibers formation and actomyosin contractility. It acts upon several effectors. Among them, ROCK1 and DIAPH1 are the best described. RhoA, and the other Rho GTPases, are part of a larger family of related proteins known as the Ras superfamily, a family of proteins involved in the regulation and timing of cell division. RhoA is one of the oldest Rho GTPases, with homologues present in the genomes since 1.5 billion years. As a consequence, RhoA is somehow involved in many cellular processes which emerged throughout evolution. RhoA specifically is regarded as a prominent regulatory factor in other functions such as the regulation of cytoskeletal dynamics, transcription, cell cycle progression and cell transformation.
Ras-related protein Rab-7a is a protein that in humans is encoded by the RAB7A 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.
Rab GDP dissociation inhibitor alpha is a protein that in humans is encoded by the GDI1 gene.
Ras-related protein Rab-11A is a protein that in humans is encoded by the RAB11A gene.
Ras-related protein Rab-4A is a protein that in humans is encoded by the RAB4A gene.
Ras-related protein Rab-1A is a protein that in humans is encoded by the RAB1A gene.
RhoG is a small monomeric GTP-binding protein, and is an important component of many intracellular signalling pathways. It is a member of the Rac subfamily of the Rho family of small G proteins and is encoded by the gene RHOG.
Ras-related protein Rab-2A is a protein that in humans is encoded by the RAB2A gene.
Ras-related protein Rab-10 is a protein that in humans is encoded by the RAB10 gene.
RAB3A-interacting protein is a protein that in humans is encoded by the RAB3IP gene.
Ras-related protein Rab-21 is a protein that in humans is encoded by the RAB21 gene.
Ras-related protein Rab-11B is a protein that in humans is encoded by the RAB11B gene. Rab11b is reported as most abundantly expressed in brain, heart and testes.
Ras-related protein Rab-8B is a protein that in humans is encoded by the RAB8B gene.
Ras and EF-hand domain-containing protein also known as Ras-related protein Rab-45 is a protein that in humans is encoded by the RASEF gene.
The TBC domain is an evolutionarily conserved protein domain found in all eukaryotes. It is approximately 180 to 200 amino acids long. The domain is named for its initial discovery in the proteins Tre-2, Bub2, and Cdc16.
Ras-related protein Rab-2B is a protein that in humans is encoded by the RAB2B gene.