page_title: RAB7A
section_title: Function
hierarchical_section_title: RAB7A / Function
caption_attribution_description: English: The endocytic pathway in animal cells. Endocytosed molecules from the cell surface are internalized to early endosomes. These then develop into late endosomes/multivesicular bodies (MVBs) by maturation; recycling molecules are removed, pH is lowered, lumenal vesicles form, and RAB5 is replaced with RAB7, making them competent for fusion with lysosomes. Fusion creates a hybrid, from which a lysosome is reformed. Molecules recycling to the plasma membrane can traffic via recycling endosomes (not shown). Molecules are also transported to/from the Golgi. More complicated pathways exist in specialized cells. Transferrin and its receptor cycle between the plasma membrane and (mainly) early endosomes. Transferrin releases its iron in the acidic endosome. EGF receptors that are activated by binding EGF, are downregulated by degradation in lysosomes. EGF binding stimulates ubiquitination of EGFRs and this targets them to the lysosome lumen, via lumenal vesicles. Mannose-6-phosphate receptors cycle between the Golgi and endosomes, releasing their cargo due to the low pH of the endosomes.
context_page_description: Ras-related protein Rab-7a is a protein that in humans is encoded by the RAB7A gene.
  Ras-related protein Rab-7a is involved in endocytosis, which is a process that brings substances into a cell. The process of endocytosis works by folding the cell membrane around a substance outside of the cell and then forms a vesicle. The vesicle is then brought into the cell and cleaved from the cell membrane. RAB7A plays an important role in the movement of vesicles into the cell as well as with vesicle trafficking.
  Various mutations of RAB7A are associated with Hereditary sensory neuropathy type 1C, also known as Charcot-Marie-Tooth syndrome type 2B.
context_section_description: Members of the RAB family of RAS-related GTP-binding proteins are important regulators of vesicular transport and are located in specific intracellular compartments. RAB7 has been localized to late endosomes and shown to be important in the late endocytic pathway. In addition, it has been shown to have a fundamental role in the cellular vacuolation induced by the cytotoxin VacA of Helicobacter pylori.
  RAB7A functions as a key regulator in endo-lysosomal trafficking, governs early-to-late endosomal maturation, microtubule minus-end as well as plus-end directed endosomal migration and positions, and endosome-lysosome transport through different protein-protein interaction cascades.
  RAB7A is also involved in regulation of some specialized endosomal membrane trafficking, such as maturation of melanosomes through modulation of SOX10 and the oncogene MYC. Mutations in the lysosomal pathway result in tumor progression in melanoma cells.
caption: Shows the role of RAB7 during endocytosis
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