SRGAP2C and the Human Mind: A Genetic Key to Cognitive Evolution

The SLIT-ROBO Rho GTPase Activating Protein 2C (SRGAP2C) gene is a human-specific ortholog of murine SRGAP2 and paralog of SRGAP2A, playing a pivotal role in cortical development and neural plasticity. Unlike SRGAP2A, SRGAP2C arose through segmental duplications unique to the Homo lineage approximately 3.4, 2.1, and 1 million years ago. These duplication events coincide with the divergence of early Homo species from Australopithecus and the emergence of increased cognitive abilities and tool use. SRGAP2C functions as a dominant-negative regulator of SRGAP2A by inhibiting its activity. This results in delayed synaptic maturation and increased density of dendritic spines, key factors thought to enhance information processing and storage in the human brain. In this study, the nucleotide and protein sequences of SRGAP2C were analyzed and compared to their orthologous sequences in Pan troglodytes. Results demonstrate high conservation between the species, yet distinct mutations in the SRGAP2C paralog contribute to its inhibitory effect on SRGAP2A. Importantly, two potential AP2_Q3 transcription factor binding sites were identified within the conserved introns of the SRGAP2C sequence, suggesting a regulatory mechanism that may influence the expression of SRGAP2C during cortical development. These sites are hypothesized to enhance the gene’s role in modulating neural differentiation and maturation. These findings offer insight into SRGAP2C’s evolutionary significance and its potential impact on the molecular mechanisms underlying human cognitive evolution.