Protein-interacting, N-terminal, Bro1-like domain of an Uncharacterized family of the BRO1_Alix_like superfamily
This domain family is comprised of uncharacterized proteins. It belongs to the BRO1_Alix_like superfamily which includes the Bro1-like domains of mammalian Alix (apoptosis-linked gene-2 interacting protein X), His-Domain type N23 protein tyrosine phosphatase (HD-PTP, also known as PTPN23), RhoA-binding proteins Rhophilin-1 and -2, Brox, Bro1 and Rim20 (also known as PalA) from Saccharomyces cerevisiae, Ustilago maydis Rim23 (also known as PalC), and related domains. Alix, HD-PTP, Brox, Bro1, Rim20 and Rim23 interact with the ESCRT (Endosomal Sorting Complexes Required for Transport) system. Alix participates in membrane remodeling processes during the budding of enveloped viruses, vesicle budding inside late endosomal multivesicular bodies (MVBs), and the abscission reactions of mammalian cell division. It also functions in apoptosis. HD-PTP and Bro1 function in endosomal trafficking, with HD-PTP having additional functions in cell migration. Rim20 and Rim23 play roles in the response to the external pH via the Rim101 pathway. Bro1-like domains are boomerang-shaped, and part of the domain is a tetratricopeptide repeat (TPR)-like structure. Bro1-like domains bind components of the ESCRT-III complex: CHMP4 (in the case of Alix, Brox and HD-PTP) and Snf7 (in the case of yeast Bro1 and Rim20). The Bro1-like domains of Alix, HD-PTP, Brox, and Rhophilin can bind human immunodeficiency virus type 1 (HIV-1) nucleocapsid. In addition to this Bro1-like domain, Alix, Bro1, Rim20, HD_PTP, and proteins belonging to this uncharacterized family, also have a V-shaped (V) domain. The Alix V-domain is a dimerization domain, and contains a binding site for the retroviral late assembly (L) domain YPXnL motif, which is partially conserved in the BRO1_Alix_like superfamily. Many members of this superfamily also have a proline-rich region (PRR), a protein interaction domain.
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