Fig. 1. Integrin cytoplasmic motifs involved in integrin trafficking. The cyto1, cyto2 and cyto3 regions of ß integrins are underlined in the ß1-integrin sequence. The cyto1 sequence is conserved in all ß integrins except ß4, but the cyto2 and cyto3 signals (NxxY) are found in all ß integrins. All three cyto motifs are important for focal adhesion localization. Cyto2 and cyto3 are involved in endocytosis of ß1 integrins (see text). The underlined ß2-integrin tail motif YRRF, the C-terminal ß3-integrin tail and the Arg1161 in 2 integrin are involved in trafficking of Lß2, avß3 and 2ß1, respectively.