Rho-related GTP-binding protein RhoB

RhoB is a small Rho-family GTPase (196 amino acids, ~22 kDa) that regulates multiple cellular processes including apoptosis, intracellular trafficking, and cytokinesis (UniProt: P62745). It mediates protein trafficking through endosomal compartments—notably targeting PKN1 to endosomes and directing EGF receptor trafficking to lysosomes—and is required for AKT1 stability and nuclear localization, which supports endothelial cell survival. RhoB also functions as a microtubule-dependent signal essential for myosin contractile ring formation during cell division (UniProt: P62745).

RhoB is implicated in tumor suppression, as its deletion promotes tumorigenesis, and it participates in genotoxic stress-induced cell death in breast cancer cells (UniProt: P62745). No primary neurodevelopmental or baseline tissue dysfunction is annotated in UniProt.

RhoB is down-regulated in Alzheimer's Disease brain tissue. Quantitative proteomics from human post-mortem AD brain versus age-matched controls detected a mean log2 fold-change of −0.53 across one subcellular fraction in a TMT-labeled DDA experiment (Chaparral AD proteomics). This down-regulation may relate to impaired protein trafficking or reduced stress-induced apoptosis in AD pathology.