Ras-related protein Rab-40B (SOCS box-containing protein RAR) (Protein Rar)
1_MSALG 6_ SPVRA 11_ YDFLL 16_ KFLLV 21_ GDSDV 26_ GKGEI 31_ LASLQ 36_ DGAAE 41_ SPYGH 46_ PAGID 51_ YKTTT 56_ ILLDG 61_ RRVKL 66_ QLWDT 71_ SGQGR 76_ FCTIF 81_ RSYSR 86_ GAQGV 91_ ILVYD 96_ IANRW 101_ SFDGI 106_ DRWIK 111_ EIDEH 116_ APGVP 121_ KILVG 126_ NRLHL 131_ AFKRQ 136_ VPTEQ 141_ AQAYA 146_ ERLGV 151_ TFFEV 156_ SPLCN 161_ FNITE 166_ SFTEL 171_ ARIVL 176_ LRHGM 181_ DRLWR 186_ PSKVL 191_ SLQDL 196_ CCRAV 201_ VSCTP 206_ VHLVD 211_ KLPLP 216_ IALRS 221_ HLKSF 226_ SMANG 231_ LNARM 236_ MHGGS 241_ YSLTT 246_ SSTHK 251_ RSSLR 256_ KVKLV 261_ RPPQS 266_ PPKNC 271_TRNSC
1: RAB40B small GTPase acts as substrate-recognition components of the ECS(RAB40B) E3 ubiquitin ligase complex which mediates the ubiquitination of target proteins (PubMed:33999101, PubMed:35293963). The Rab40 subfamily belongs to the Rab family that are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different sets of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion (PubMed:27789576). As part of the ECS(RAB40B) complex, GTP-bound RAB40B promotes LIMA1/EPLIN ubiquitination and degradation, thereby regulating leading-edge actin dynamics during cell migration (PubMed:33999101). As part of the ECS(RAB40B) complex, GTP-bound RAB40B also ubiquitinates RAP2A GTPase which promotes its localization to lamellipodia and activation to drive cell migration. The ECS(RAB40B) complex does not mediate canonical ubiquitin-dependent degradation of RAP2 (PubMed:35293963). RAB40B also binds TKS5/SH3PXD2A effector independently from ECS complex to promote invadopodia-mediated extracellular matrix degradation (PubMed:27789576)