Tumor susceptibility gene 101, also known as TSG101, is a human gene that encodes for a cellular protein of the same name.
The protein encoded by this gene belongs to a group of apparently inactive homologs of ubiquitin-conjugating enzymes. The gene product contains a coiled-coil domain that interacts with stathmin, a cytosolic phosphoprotein implicated in tumorigenesis. The protein may play a role in cell growth and differentiation and act as a negative growth regulator. In vitro steady-state expression of this tumor susceptibility gene appears to be important for maintenance of genomic stability and cell cycle regulation. Mutations and alternative splicing in this gene occur in high frequency in breast cancer and suggest that defects occur during breast cancer tumorigenesis and/or progression. [5]
The main role of TSG101 is to participate in ESCRT pathway. This pathway facilitates reverse topology budding and formation of multivesicular bodies (MVB) which delivers cargo destined for degradation to the lysosomes. [6] TSG101 recognises short linear motif : P(T/S)AP via the UEV protein domain of the VPS23/TSG101 subunit. The assembly of the ESCRT-I complex is directed by the C-terminal steadiness box (SB) of VPS23, the N-terminal half of VPS28, and the C-terminal half of VPS37. The structure is primarily composed of three long, parallel helical hairpins, each corresponding to a different subunit. The additional domains and motifs extending beyond the core serve as gripping tools for ESCRT-I critical functions. [7] [8]
TSG101 plays an important role in the pathogenesis of HIV and other viruses. In uninfected cells, TSG101 functions in the biogenesis of the multivesicular body (MVB), [9] which suggests that HIV may bind TSG101 in order to gain access to the downstream machinery that catalyzes MVB vesicle budding. [10]
TSG101 has been shown to interact with:
Vps23_core | |||||||||
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Identifiers | |||||||||
Symbol | Vps23_core | ||||||||
Pfam | PF09454 | ||||||||
InterPro | IPR017916 | ||||||||
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In humans, the orthologue of vps23 which has a component of ESCRT-1 is called Tsg101. Mutations in Tsg-101 have been linked to cervical, breast, prostate and gastrointestinal cancers. In molecular biology, vps23 (vacuolar protein sorting) is a protein domain. Vps proteins are components of the ESCRTs (endosomal sorting complexes required for transport) which are required for protein sorting at the early endosome. More specifically, vps23 is a component of ESCRT-I. The ESCRT complexes form the machinery driving protein sorting from endosomes to lysosomes. ESCRT complexes are central to receptor down-regulation, lysosome biogenesis and budding of HIV.
Yeast ESCRT-I consists of three protein subunits, VPS23, VPS28, and VPS37. In humans, ESCRT-I comprises TSG101, VPS28, and one of four potential human VPS37 homologues.
E3 ubiquitin-protein ligase NEDD4, also known as neural precursor cell expressed developmentally down-regulated protein 4 is an enzyme that is, in humans, encoded by the NEDD4 gene.
Protein numb homolog is a protein that in humans is encoded by the NUMB gene. The protein encoded by this gene plays a role in the determination of cell fates during development. The encoded protein, whose degradation is induced in a proteasome-dependent manner by MDM2, is a membrane-bound protein that has been shown to associate with EPS15, LNX1, and NOTCH1. Four transcript variants encoding different isoforms have been found for this gene.
Charged multivesicular body protein 2b is a protein that in humans is encoded by the CHMP2B gene. It forms part of one of the endosomal sorting complexes required for transport (ESCRT) - specifically ESCRT-III - which are a series of complexes involved in cell membrane remodelling. CHMP2B forms long chains that spiral around the neck of a budding vesicle. Along with the other components of ESCRT-III, CHMP2B constricts the neck of the vesicle just before it is cleaved away from the membrane.
Autocrine motility factor receptor, isoform 2 is a protein that in humans is encoded by the AMFR gene.
MAP kinase-activating death domain protein is an enzyme that in humans is encoded by the MADD gene.
Charged multivesicular body protein 3 is a protein that in humans is encoded by the VPS24 gene.
Ubiquitin-conjugating enzyme E2 G2 is a protein that in humans is encoded by the UBE2G2 gene.
Vacuolar protein sorting-associated protein 28 homolog is a protein that in humans is encoded by the VPS28 gene.
Charged multivesicular body protein 4b is a protein that in humans is encoded by the CHMP4B gene.
Charged multivesicular body protein 4a is a protein that in humans is encoded by the CHMP4A gene.
Charged multivesicular body protein 5 is a protein that in humans is encoded by the CHMP5 gene.
Charged multivesicular body protein 6 is a protein that in humans is encoded by the CHMP6 gene. It is one of charged multivesicular body proteins and a part of endosomal sorting complexes required for transport-III (ESCRT-III) complex.
Charged multivesicular body protein 2a is a protein that in humans is encoded by the CHMP2A gene.
It is a reference gene.
Vacuolar protein-sorting-associated protein 36 is a protein that in humans is encoded by the VPS36 gene.
Charged multivesicular body protein 1b is a protein that in humans is encoded by the CHMP1B gene.
E3 ubiquitin-protein ligase LRSAM1, previously known as Tsg101-associated ligase (Tal), is an enzyme that in humans is encoded by the LRSAM1 gene.
Vacuolar-sorting protein SNF8 is a protein that in humans is encoded by the SNF8 gene.
Vacuolar protein-sorting-associated protein 25 is a protein that in humans is encoded by the VPS25 gene.
RING finger protein 139, also known as TRC8, is a protein that in humans is encoded by the RNF139 gene.
The endosomal sorting complexes required for transport (ESCRT) machinery is made up of cytosolic protein complexes, known as ESCRT-0, ESCRT-I, ESCRT-II, and ESCRT-III. Together with a number of accessory proteins, these ESCRT complexes enable a unique mode of membrane remodeling that results in membranes bending/budding away from the cytoplasm. These ESCRT components have been isolated and studied in a number of organisms including yeast and humans. A eukaryotic signature protein, the machinery is found in all eukaryotes and some archaea.