Plant GTPases: the Rhos in bloom

In animal cells and in fungi, small GTP-binding proteins of the Rho family have well-established roles in morphogenesis, cell-cycle progression, gene transcription and the generation of superoxide anions. The presence of thes e proteins in plant cells, however, has been established only recently, and the role of Rho GTPases in plants is now coming into view. Already, it is apparent that there are both striking similarities and fascinating differen ces in how Rho GTPases are regulated and used in plant versus animal and fu ngal cells. These new findings define certain core properties that might be common to members of this protein family in all eukaryotes.