Table 1.
Small GTPases interacting with calmodulin. The various GTPases, their functions, the methodologies to assess their interaction with calmodulin, the cell lines analyzed, the calmodulin function as well as their interacting domains or protein sequences are listed. The relevant references are also given. Abbreviations: AC, affinity chromatography; BRET, bioluminescence resonance energy transfer; CBR, calmodulin binding region (basic amino acids are in red); CoIP, coimmunoprecipitation; CompMod, computational modelling; FS, fluorescence spectrometry; PXL, peptide cross-linking; RC, reconstituted complex; SF-TAP, Strep/Flag tandem affinity purification; YTH, yeast two hybrid.
| GTPase | Function | Interaction method | Species | Calmodulin (CaM) action | Refs |
|---|---|---|---|---|---|
| Cdc42 | Filopodia formation and cell-cycle progression | CoIP, AC, RC | Human (platelets) | Cdc42 inhibition CBR:151AVKYVECSALTQK164 (hypothetical amphipathic α-helix) |
[23] |
| AC | Human (MCF-7) | Regulation of Cdc42 signalling through IQGAP1 | [48] | ||
| Kir/Gem | Cell proliferation, Neurite extension and flattening (Gem); invasion and metastasis (Kir). Inhibition of Ca2+ channels (Kir/Gem) |
FS, RC | Synthetic peptides, in vitro | Kir/Gem inactivation (inhibits GTP binding), regulates intracellular localization CBR:264/265KARRFWGKIVAKNNKNMAFKLKSKS288/289 (hypothetical amphipathic α-helix) |
[31] |
| Xenopus oocytes | Inhibition of high voltage-activated calcium channels and regulation of intracellular distribution | [63] | |||
| Monkey (COS-1) | Regulate intracellular localization between cytoplasm and nucleus, in a complex with 14-3-3 | [61] | |||
| CoIP, RC | Monkey (COS-1) | Inhibits association with importin α5 and nuclear translocation | [66] | ||
| KRas-4B | Cell proliferation, differentiation, survival and apoptosis | CoIP, AC, RC | Mouse (NIH3T3) | KRas inactivation | [19] |
| RC, YTH. | Human (platelets) | Down-regulation of KRas signalling and KRas membrane transport | [20] | ||
| AC | Mouse (NIH3T3) | CBR:151GVDDAFYTLVREIRKH166 (amphipathic α-helix5) CBR: C-terminal prenyl group |
[16] | ||
| RC | CBR:170KMSKDGKKKKKSKTKC185+ prenyl CBR:180KSKTKC185+prenyl group |
[67,68] | |||
| AC | Mouse (NIH3T3) | Inhibits KRas Ser181 phosphorylation | [29] | ||
| Rab3A | Synaptic and axonal transport. Regulated exocytosis in neuronal and endocrine cells |
PXL | Rat brain synaptosomes |
Dissociation of Rab3A from synaptic membranes CBR:62KTIYRNDKRIKLQIWDTA GQERYR85 |
[36,69] |
| Rat (PC12) | Inhibition of exocytosis | [30] | |||
| CoIP, PXL | Rat (pancreatic islets) | Inhibits insulin secretion | [42] | ||
| Rat brain synaptosomes | Promotes GTP binding | [70] | |||
| Human (spermatozoa from sperm donors) | Acrosomal exocytosis | [71] | |||
| Rab3B | Calcium-dependent exocytosis | AC | Mouse brain | [10] | |
| RC | Human (platelets) | Ca2+-dependent secretion in platelets | [33] | ||
| Rab3D | Maintenance of osteoclastic border membrane | AC | Mouse brain | [10] | |
| YTH, BRET, RC | Monkey (COS-1, reconstituted complex) | Promotes osteoclastic bone resorption | [46] | ||
| Rabs: 6B, 8B,10, 15, 33B, 37. | AC | Mouse brain | [10] | ||
| Rac1 | Cytoskeletal organization, migration, adhesion, proliferation, endocytosis, vesicular trafficking | CoIP, AC, RC | Human (platelets) | Rac1 activation CBR:151AVKYLECSALTQRG164 (hypothetical amphipathic α-helix) |
[23] |
| AC, RC, CompMod | Human (HeLa) | Rac1 activation | [21] | ||
| AC | Monkey (COS-1) | Rac1 activation Impairs binding to PIP5K CBR:171EAIRAVLCPPPVKKRKRK188 and the C-terminal prenyl group |
[22] | ||
| SF-TAP | Human (HEK293T) | [72] | |||
| Rad | Skeletal muscle motor function, cytoskeletal organization and glucose transport | RC | GST-Rad incubated with CaM-sepharose in vitro | Regulates intracellular localization CBR:278AKRFLGRIVARNSRKMA FRA297 (hypothetical amphipathic α-helix) |
[31] |
| [65] | |||||
| RalA | Cell proliferation, migration, filopodia formation, differentiation, cytoskeletal organization, vesicular transport, exocytosis and receptor endocytosis. Synaptic and axonal transport |
AC, RC, YTH | Human (platelets) | RalA activation | [38] |
| RC | Human (HeLa) | RalA activation CBR: C-terminal prenyl group |
[39] | ||
| Rat brain synaptosomes | Dissociation of RalA from synaptic membranes | [69] | |||
| Purified RalA, in vitro | Regulates GTP binding CBR:183SKEKNGKKKRKSLAKRIR200 (hypothetical amphipathic α-helix) |
[34,40] | |||
| Rat brain synaptosomes | Regulates GTP binding | [73] | |||
| RalB | Cell proliferation, oncogenic transformation | CoIP, AC, RC, YTH | Human (platelets) | RalB activation CBR: C-terminal prenyl group |
[38,39] |
| Rat brain synaptosomes | Regulates GTP binding | [73] | |||
| Rem | Ca2+channel regulation | CoIP, AC | Human (HEK293, TSA20) | No Ca2+ channel inhibition CBR:165QRARRFLARLTARSARRR282 |
[74] |
| Ric | Dot-blot, AC, CoIP | Drosophila | Regulation of Ca2+-mediated neuronal signal transduction CBR:242RRSRWWRIRSIFALVFRR RR261 |
[35] | |
| Drosophila (cross of Ric mutants with CaM mutants) | Ric inhibition | [56] | |||
| Rin | Ca2+ signalling in neurons | Dot-blot | Mouse |
Regulation of calcium-mediated neuronal signal transduction CBR:194RKLKRKDSLWKKIKASLKKKRENML218 |
[32] |
| CoIP | Monkey (COS-7) | Regulation of Rin activation | [54] | ||
| Rat (PC12) | Induce neurite outgrowth | [55] |