TGF-beta-receptor-mediated signaling.

Transforming growth factor beta (TGF-beta) and its many relatives are thought to play key roles in the control of cell proliferation and differentiation. In particular, the ability of TGF-beta to induce growth arrest in epithelial cells has drawn considerable attention. The recent cloning of TGF-beta receptors, which are considered to be prototypes of a new class of cell-surface receptors, has provided a first insight into how TGF-beta signaling induces a variety of intracellular changes. Furthermore, recent advances in the characterization of the cell-cycle machinery have stimulated studies aimed at understanding how TGF-beta signaling leads to growth arrest in the late G1 phase of the cell cycle.