The secreted Slit repellents and their Roundabout (Robo) receptors were originally identified as important axon guidance molecules. The SLIT-ROBO interaction has been found to be involved in the regulation of cell migration, cell death and angiogenesis and, as such, has a pivotal role during the development of other tissues such as the lung, kidney, liver and breast []. There are four Robo homologues in vertebrates (Robo1-4).Robo1 and Robo2 are known to play a crucial role in axon guidance [, ]. They overlap to cooperate in guiding longitudinal axons, but each isoform has specialised functions in spinal commissural axon guidance [, ]. Robo1 prevents axonal stalling after crossing []. Robo1 may also be involved in lung []and heart development [, ].Deregulation of Robo is implicated in several neuropathological conditions and cancers [].
The SLIT-ROBO Rho GTPase-activating protein (srGAP) family consists of four members: srGAP1, -2, -3 and -4. They contain F-BAR, RhoGAP and SH3 domains. Their RhoGAP domain is involved in negative regulation of Rho GTPase activities important for cytoskeleton rearrangement []. The srGAP family members have an "inverse F-BAR"or IF-BAR domain that is distinct from other F-BAR domains such as FBP17. They are multifunctional adaptor proteins involved in various aspects of neuronal development [].This entry represents the F-BAR domain of srGAP1. srGAP1, also called Rho GTPase-Activating Protein 13 (ARHGAP13), is a Cdc42- and RhoA-specific GAP and is expressed later in the development of CNS (central nervous system) tissues. It is an important downstream signaling molecule of Robo1 [, ].
