Structural highlights
Function
[GGA1_HUMAN] Plays a role in protein sorting and trafficking between the trans-Golgi network (TGN) and endosomes. Mediates the ARF-dependent recruitment of clathrin to the TGN and binds ubiquitinated proteins and membrane cargo molecules with a cytosolic acidic cluster-dileucine (AC-LL) motif.[1] [SORL_HUMAN] Likely to be a multifunctional endocytic receptor, that may be implicated in the uptake of lipoproteins and of proteases. Binds LDL, the major cholesterol-carrying lipoprotein of plasma, and transports it into cells by endocytosis. Binds the receptor-associated protein (RAP). Could play a role in cell-cell interaction.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The cytosolic adaptors GGA1-3 mediate sorting of transmembrane proteins displaying a C-terminal acidic dileucine motif (DXXLL) in their cytosolic domain. GGA1 and GGA3 contain similar but intrinsic motifs that are believed to serve as autoinhibitory sites activated by the phosphorylation of a serine positioned three residues upstream of the DXXLL motif. In the present study, we have subjected the widely acknowledged concept of GGA1 autoinhibition to a thorough structural and functional examination. We find that (i) the intrinsic motif of GGA1 is inactive, (ii) only C-terminal DXXLL motifs constitute active GGA binding sites, (iii) while aspartates and phosphorylated serines one or two positions upstream of the DXXLL motif increase GGA1 binding, phosphoserines further upstream have little or no influence and (iv) phosphorylation of GGA1 does not affect its conformation or binding to Sortilin and SorLA. Taken together, our findings seem to refute the functional significance of GGA autoinhibition in particular and of intrinsic GGA binding motifs in general.
GGA Autoinhibition Revisited.,Cramer JF, Gustafsen C, Behrens MA, Oliveira CL, Pedersen JS, Madsen P, Petersen CM, Thirup SS Traffic. 2010 Feb;11(2):259-73. Epub 2009 Nov 10. PMID:20015111[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Puertollano R, Randazzo PA, Presley JF, Hartnell LM, Bonifacino JS. The GGAs promote ARF-dependent recruitment of clathrin to the TGN. Cell. 2001 Apr 6;105(1):93-102. PMID:11301005
- ↑ Cramer JF, Gustafsen C, Behrens MA, Oliveira CL, Pedersen JS, Madsen P, Petersen CM, Thirup SS. GGA Autoinhibition Revisited. Traffic. 2010 Feb;11(2):259-73. Epub 2009 Nov 10. PMID:20015111 doi:http://dx.doi.org/TRA1017
