▪ Abstract The p21-activated kinases (PAKs) 1–3 are serine/threonine protein kinases whose
activity is stimulated by the binding of active Rac and Cdc42 GTPases. Our understanding of …

Cdc42p is an essential GTPase that belongs to the Rho/Rac subfamily of Ras-like GTPases.
These proteins act as molecular switches by responding to exogenous and/or endogenous …

How membrane receptors initiate signal transduction upon ligand binding is a matter of
intense scrutiny. The T cell receptor complex (TCR-CD3) is composed of TCRα/β ligand …

The p21-activated kinases (PAKs), stimulated by binding with GTP-liganded forms of Cdc42
or Rac, modulate cytoskeletal actin assembly and activate MAP-kinase pathways. The 2.3 Å …

The mitogen-activated protein kinase–extracellular signal–regulated kinase signaling
element (MAPK-ERK) plays a critical role in natural killer (NK) cell lysis of tumor cells, but its …

The Wiskott-Aldrich syndrome protein (WASp) has been implicated in modulation of
lymphocyte activation and cytoskeletal reorganization. To address the mechanisms whereby …

SH2/SH3 domain-containing adapter proteins, such as the Nck family, play a major role in
regulating tyrosine kinase signalling. They serve to recruit proline-rich effector molecules to …

Members of the Pak family of serine/threonine kinases serve as targets for the small GTP-
binding proteins Cdc42 and Rac and have been implicated in a wide range of biological …

Itk, a Tec family tyrosine kinase, acts downstream of Lck and phosphatidylinositol 3′-kinase
to facilitate T cell receptor (TCR)-dependent calcium influxes and increases in extracellular …

The SH2/SH3 adaptor protein Dock has been proposed to transduce signals from guidance
receptors to the actin cytoskeleton in Drosophila photoreceptor (R cell) growth cones. Here …