The evolutionary history of effectors downstream of Cdc42 and Rac

Table 1 Cdc42 and Rac effectors

Effectors	Biological functions
Actin-associated proteins
Formins	Actin polymerization; cell polarity; cytokinesis
IQGAP1	Actin organization; regulation of cell-cell contacts
WASP	Actin polymerization
WAVE	Actin polymerization
p140^Sra-1	Actin organization
Adaptor proteins
POSH	Jnk/NFκB activation
Par6	Cell polarity
Lipid kinases
DGK	Phosphatidic acid levels; maybe also actin regulation
PI3K	PIP₃ levels; actin organization
PI5K	PIP₂ levels; actin organization
Miscellaneous proteins
Borg	Actin organization
CIP4	Actin organization
NADPH oxidase	ROS production; apoptosis
POR1	Actin organization
SPEC	Actin organization
Phospholipases
PLC-β	DAG/IP3 levels
PLD	Phosphatidic acid levels; cytoskeletal reorganization
Serine/threonine kinases
MEKK	Jnk activation
MLK	Jnk activation
MRCK	Actin organization
Pak	Actin organization; MAPK/Jnk activation; apoptosis
p70^S6K	Transcription; cell-cycle progression; RNA processing
Tyrosine kinases
Ack	Actin organization

Abbreviations: Ack, activated cdc42-associated tyrosine kinase; Borg, binder of Rho GTPases; CIP4, Cdc42-interacting protein; DAG, diacylglycerol; DGK, diacylglycerol kinase; IP3, inositol trisphosphate; MEKK, mitogen-activated protein kinase (MAPK) kinase; MLK, mixed-lineage kinase; MRCK, myotonic dystrophy kinase-related Cdc42-binding kinase; NADPH, nicotinamide adenine dinucleotide phosphate; Pak, p21-activated kinase; Par, partitioning defective; PIP₂, phosphatidylinositol 4,5-bisphosphate; PIP₃, phosphatidylinositol 3,4,5-trisphosphate; PI3K, phosphatidylinositol 3-kinase; PI5K, phosphatidylinositol 4-phosphate-5 kinase; PLC, phospholipase C; PLD, phospholipase D; POR1, partner of Rac; POSH, plenty of SH3 domains; p70^S6K, 70 kDa ribosomal S6 kinase; p140^Sra-1, specifically Rac1-associated protein; SPEC, small protein effector of Cdc42; WASP, Wiskott Aldrich syndrome protein; WAVE, WASP-like verproline-homologous protein.

ISSN: 1474-760X