We identified a 116-kD protein, termed p116 Rip , that binds to activated RhoA under two-hybridconditions in yeast. Pull-down experiments in mouse N1E-115 neuroblastoma cells revealed aninteraction between GST-RhoA and a protein of that comigrates with p116Rip and is recognizedby anti?p116Rip antibody (Fig. 5 D). While this protein does not interact with GST alone, ourrecent experiments indicate that it is not p116 Rip but an unidentified bacterial protein that hasthe same apparent molecular size as p116 Rip and cross-reacts with the anti?p116 Rip antibodyused. Therefore, the conclusion that p116 Rip interacts with RhoA in N1E-115 cells is premature.Overexpression of p116 Rip in N1E-115 cells mimics dominant-negative RhoA in stimulating cellflattening and neurite outgrowth. We are currently characterizing p116 Rip in further biochemicaldetail and evaluating the relationship between p116 Rip and RhoA action. We apologize for any additional work that our error may have caused other investigators.