Ras-related protein Ral-A

Ras-related protein Ral-A (RALA) is a multifunctional small GTPase that regulates diverse cellular processes including gene expression, cell migration, proliferation, and membrane trafficking through interactions with distinct downstream effectors (UniProt: P11233). The protein functions as a GTP sensor for exocytosis of dense core vesicles and controls integrin-dependent membrane raft exocytosis, mitochondrial fission, and cytokinesis through its interactions with the exocyst complex and other regulatory proteins.

RALA is broadly expressed and participates in fundamental cellular processes spanning from signal transduction to organellar dynamics. A rare autosomal dominant neurodevelopmental disorder, Hiatt-Neu-Cooper syndrome (HINCONS), has been associated with RALA mutations, presenting with global developmental delay, impaired intellectual development, and variable seizures or behavioral abnormalities (UniProt: P11233).

In Alzheimer's disease, RALA is significantly downregulated in post-mortem AD brain tissue relative to age-matched controls, with a mean log2 fold-change of −0.50 across subcellular fractions (Chaparral AD proteomics). This downregulation suggests potential involvement in AD pathophysiology, though the functional consequences of reduced RALA expression in neurodegeneration require further investigation.