Downstream factors in transforming growth factor-beta family signaling

The recently identified family of Smad proteins has given insight in the un derstanding of how members of the transforming growth factor-beta (TGF-beta ) family relay their signal to the nucleus. Besides Smad proteins, G protei ns and MAPKs are also involved in the downstream signaling of TGF-beta fami ly members. The identification of elements that function downstream in the TGF-beta signaling pathway and the fact that these downstream players can i nteract with the signaling cascade of other growth factors, may give insigh t into the diverse biological responses evoked by the TGF-beta family membe rs. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.