RalB regulation pathway
V-ral simian leukemia viral oncogene homolog B ( RalB ) is small GTPase. It belongs to the Ras superfamily of low molecular mass (20-30 kDa) GTP-binding proteins that influence cytoskeleton remodeling processes, endo- and exocytosis , , .
Activated v-Ha-ras Harvey rat sarcoma viral oncogene homolog ( H-Ras ) can modulate activity of RalB by recruiting Ral guanine nucleotide dissociation stimulator ( RalGDS ) that is shown to exhibit GEF activity towards RalB , , , .
Small GTPase Ras-like without CAAX 1 ( RIT ) can also activate RalB via binding to Ral guanine nucleotide dissociation stimulator-like 3 ( RGL3 ) and stimulating its GEF activity .
GTP-bound RalB binds to RalA binding protein 1 ( RalBP1 ) and promotes activation of Cell division cycle 42 ( CDC42 ) and Ras-related C3 botulinum toxin substrate 1 ( RAC1 ) signaling pathways. In addition, RalB forms complexes with RalBP1, RALBP1 associated Eps domain containing 1 ( REPS1 ) and RALBP1 associated Eps domain containing 2 ( REPS2 ). This leads to stimulation of endocytosis , .
RalB is able to stimulate Phospholipase C delta 1 ( PLC-delta 1 ) enzymatic activity independent of its guanine nucleotide status .