FIG. 7.

Model of JSRV Env-induced transformation. A proposed model for signaling in JSRV Env-induced transformation is shown. JSRV envelope protein leads directly or indirectly to activation of the Ras-MEK-MAPK and PI3K-Akt-mTOR pathways as well as to activation of p38 MAPK, which negatively regulates transformation. Question marks indicate alternate pathways that are inferred from the data, but the identities of the key proteins are not known. Sizes of the arrows reflect the relative importance for transformation. The arrows do not necessarily indicate direct binding and/or activation of the downstream molecules; intermediate proteins or kinases may exist.