Internalization, recycling and lysosomal sorting are key processes that regulate the temporal and spatial signaling of G protein-coupled receptors (GPCRs). Interactions between GPCR intracytosolic sorting signals and adaptor proteins facilitate trafficking through the endocytic pathway. To date only a few sorting signals and molecules that regulate GPCR trafficking have been identified. A study...

The protein product of the gene responsible for ocular albinism type 1, named OA1, is a pigment-cell-specific membrane glycoprotein, displaying features of G-protein-coupled receptors, yet exclusively localized to late endosomes, lysosomes and melanosomes. To dissect the signals responsible for the intracellular localization of OA1, we generated chimeric proteins consisting of the cytosolic dom...

Potter, Beth A., Rebecca P. Hughey, and Ora A. Weisz. Role of Nand O-glycans in polarized biosynthetic sorting. Am J Physiol Cell Physiol 290: C1–C10, 2006; doi:10.1152/ajpcell.00333.2005.—The maintenance of proper epithelial function requires efficient sorting of newly synthesized and recycling proteins to the apical and basolateral surfaces of differentiated cells. Whereas basolateral protein...

Sorting of transmembrane proteins to endosomes and lysosomes is mediated by signals present within the cytosolic domains of the proteins. Most signals consist of short, linear sequences of amino acid residues. Some signals are referred to as tyrosine-based sorting signals and conform to the NPXY or YXXO consensus motifs. Other signals known as dileucine-based signals fit [DE]XXXL[LI] or DXXLL c...

Cytoplasmic coat protein complexes perform central roles in sorting protein constituents within the endomembrane system. A new study reveals that the COPII coat operates through dual recognition of signals in a sorting receptor and its bound cargo to promote efficient export from the endoplasmic reticulum.

Pex3 is an evolutionarily conserved type III peroxisomal membrane protein required for peroxisome formation. It is inserted into the ER membrane and sorted via an ER subdomain (the peroxisomal ER, or pER) to peroxisomes. By constructing chimeras between Pex3 and the type III ER membrane protein Sec66, we have been able to separate the signals that mediate insertion of Pex3 into the ER from thos...

LOCATE is a curated, web-accessible database that houses data describing the membrane organization and subcellular localization of mouse and human proteins. Over the past 2 years, the data in LOCATE have grown substantially. The database now contains high-quality localization data for 20% of the mouse proteome and general localization annotation for nearly 36% of the mouse proteome. The proteom...