Hello David Schad

Rac1 was originally identified in 1989 in human platelets as a substrate of the botulinum toxin from which its name derives as Ras-related C3 botulinum toxin substrate.

Please refer to the article attached below for more information.

https://pubmed.ncbi.nlm.nih.gov/2674130/

Rac1 belongs to the Rho family of small guanosine triphosphatases (GTPases) and is ubiquitously expressed. It exists in two conformational states, an inactive GDP-bound form and an active GTP-bound form. The transition from one form to another occurs upon stimuli and depends on GTPase-activating proteins (GAPs), which inactivate Rac1, and guanine nucleotide exchange factors (GEFs), which convert Rac1 to its active form.

Rac1 has diverse and broad cellular functions. It serves as a conformational switch in several signal transduction pathways. One of its primary functions identified, far away the most characterized, is the regulation of actin cytoskeleton organization and dynamics, in the migratory structures such as filopodia and lamellipodia. Other functions include the role in cell polarity, gene expression, cell-cycle progression, and cell survival.

You may want to refer to the article attached below.

https://www.omim.org/entry/602048

Best.