VZV gB endocytosis and golgi localization are mediated by YXX phi motifs in its cytoplasmic domain

The cytoplasmic domains of many membrane proteins contain sorting signals t hat mediate their endocytosis from the plasma membrane. VZV gB contains thr ee consensus internalization motifs within its cytoplasmic domain: YMTL (aa 818-821), YSRV (aa 857-860), and LL (aa 841-842). To determine whether VN gB is internalized from the plasma membrane, and whether these motifs are r equired for its endocytosis, we compared the internalization of native gB t o that of gB containing mutations in each of the predicted internalization motifs. VN gB present on the surface of transfected cells associated with c lathrin and was efficiently internalized to the Golgi apparatus within 60 m in at 37 degreesC. VN gB containing the mutation Y857 failed to be internal ized, while gB-Y818A was internalized but did not accumulate in the Golgi. These data indicate that the internalization of VZV gB, and its subsequent localization to the Golgi, is mediated by two tyrosine-based sequence motif s in its cytoplasmic domain. (C) 2001 Academic Press.