Figure 7.

Models of LAT-1 Signaling

(A) Summary figure of structure-function correlation for two different activities of the LAT-1 receptor. Two models of receptor function incorporate these findings.

(B and C) Homodimerization through the RBL domain (a) initiates the 7TM-dependent LAT-1 activity (b). (B) In the bidirectional signaling model, the LAT-1 ectodomain interacts in trans with a molecule on the adjacent membrane through which a reverse signal (c) is conveyed to the neighboring cell. (C) The bimodal forward signaling model places LAT-1 in a cis-interaction with a molecule on the same cell membrane. This model accommodates a coreceptor sensing the same stimulus as the LAT-1 ectodomain and transducing a signal (c) parallel to the 7TM-dependent signal of LAT-1.