European Regional Development Fund(GINOP-2.3.2-15-2016-00020) Támogató: GINOP
(Open access funding provided by Semmelweis University)
ARHGAP25, a crucial molecule in immunological processes, serves as a Rac-specific
GTPase-activating protein. Its role in cell migration and phagocyte functions, affecting
the outcome of complex immunological diseases such as rheumatoid arthritis, renders
it a promising target for drug research. Despite its importance, our knowledge of
its intracellular interactions is still limited. This study employed proteomic analysis
of glutathione S-transferase (GST)-tag pulldowns and co-immunoprecipitation from neutrophilic
granulocyte cell lysate, revealing 76 candidates for potential physical interactions
that complement ARHGAP25’s known profile. Notably, four small GTPases (RAC2, RHOG,
ARF4, and RAB27A) exhibited high affinity for ARHGAP25. The ARHGAP25–RAC2 and ARHGAP25–RHOG
interactions appeared to be affected by the activation state of the small GTPases,
suggesting a GTP–GDP cycle-dependent interaction. In silico dimer prediction pinpointed
ARHGAP25’s GAP domain as a credible binding interface, suggesting its suitability
for GTP hydrolysis. Additionally, a list of Fc receptor-related kinases, phosphatases,
and three of the 14-3-3 members were identified as potential partners, with in silico
predictions highlighting eight binding sites, presenting novel insight on a potential
regulatory mechanism for ARHGAP25.
