Send to

Choose Destination
Traffic. 2010 Jun;11(6):843-55. doi: 10.1111/j.1600-0854.2010.01056.x. Epub 2010 Mar 4.

A screen for endocytic motifs.

Author information

University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.


Sorting signals for cargo selection into coated vesicles are usually in the form of short linear motifs. Three motifs for clathrin-mediated endocytosis have been identified: YXXPhi, [D/E]XXXL[L/I] and FXNPXY. To search for new endocytic motifs, we made a library of CD8 chimeras with random sequences in their cytoplasmic tails, and used a novel fluorescence-activated cell sorting (FACS)-based assay to select for endocytosed constructs. Out of the five tails that were most efficiently internalized, only one was found to contain a conventional motif. Two contain dileucine-like sequences that appear to be variations on the [D/E]XXXL[L/I] motif. Another contains a novel internalization signal, YXXXPhiN, which is able to function in cells expressing a mutant mu2 that cannot bind YXXPhi, indicating that it is not a variation on the YXXPhi motif. Similar sequences are present in endogenous proteins, including a functional YXXXPhiN (in addition to a classical YXXPhi) in cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Thus, the repertoire of endocytic motifs is more extensive than the three well-characterized sorting signals.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center