Sorting nexins are a large group of proteins that are localized in the cytoplasm and have the potential for membrane association either through their lipid-binding PX domain (a phospholipid-binding motif) or through protein–protein interactions with membrane-associated protein complexes Some members of this family have been shown to facilitate protein sorting.
Family members
In humans, sorting nexins are transcribed from the following genes:
Genes Domain Composition N-terminus Mid-1Mid-2 Mid-3 C-terminus SNX1, SNX2 Sorting_nexin_N – PX – BAR (Vps5) SNX4, SNX7, SNX8, SNX30 – – PX – BAR (Vsp5) SNX5, SNX6, SNX32 – – PX – BAR SNX9, SNX18, SNX33 SH3 – PX – BAR (BAR_3_WASP_bdg)BAR_3_WASP_bdg: WASP-binding domain of Sorting nexin protein, SNX13, SNX14, SNX19, SNX25 PXAPXA: PXA domain, RGS PX – Nexin_C SNX15 – – PX – MITMIT: MIT (microtubule interacting and transport) domain, SNX17, SNX31 – – PX RARA: Ras association (RalGDS/AF-6) domain, FERM_MFERM_M: FERM central domain, SNX23 kinesin_motor SMAD_FHASMAD_FHA: SMAD/FHA domain, PX – – SNX26 – – PX SH3 RhoGAP SNX27 PDZ – PX - FERM_MFERM_M: FERM central domain, SNX28 – – PX SH3 SH3 SNX3, SNX10, SNX11, SNX12, SNX16, SNX20, SNX21, SNX22, SNX24, SNX29 – – PX – –
Structure
Sorting nexins either consist solely of a PX domain (e.g. SNX3) or have a modular structure made up of the PX and additional domains.
A subgroup of sorting nexins (comprising, in humans, SNX1, SNX2, SNX4, SNX5, SNX6, SNX7, SNX8, SNX9, SNX18, SNX30, SNX32 and SNX33) possess a BAR domain at their C-terminus. (The BAR domain of SNXs 1, 2, 4, 7, 8 and 30 is classified by pfam as 'Vps5 C terminal like'.)
An example of a sorting nexin domain structure can be seen here for SNX1:
NTD – N-terminal domain PX domain CTD – C-terminal BAR domain
References
External links