RgIA (P02585) Protein Card

General Information

Name	RgIA
Alternative name(s)	Rg1a
Organism	Conus regius
Organism region	Eastern Pacific
Organism diet	vermivorous
Protein Type	Wild type
Protein precursor	RgIA precursor (593)
Notes	This protein sequence has been predicted from the protein prosequence (Ellison et al., 2006). The final arginine is usually cleaved by an enzyme (CPE). The sequence Reg1e, a protein directly purified from the venom duct, seems to be the real mature peptide corresponding to the precursor sequence (it presents an hydroxyproline, a N-terminal amidation and does not have the arginine). Rg1A (100 nm) significantly inhibited HVA Ca²⁺ channel currents in rat DRG neurons to 60.6 ± 4.5% of control (Callaghan et al., 2008). Inhibition of N-type Ca²⁺ channel current through the GABA_B in a9 KO mouse DRG neurons with an IC50 of 22.4 nM (Callaghan et al., 2010). The specific receptor remains unclear. Inhibited HVA Ca²⁺ channel current via GABA_B receptors in rat DRG neurons with an IC50 of 14.7 nM. (Halai et al., 2011) Alsharari et al.(2020) reported that RgIA reverses colitis signs in murine dextran sodium sulfate model. RgIA promotes the proliferation of glioma C6 cells (Terpinskaya et al., 2021). Bony et al. (2022) demonstrated that 1 µM RgIA potentiated G protein coupled inwardly-rectifying potassium (GIRK)1/2 when co-expressed with human G protein-coupled GABA_B receptors in HEK293T cells.

Classification

Conopeptide class	conotoxin
Gene superfamily	A superfamily
Cysteine framework	I
Pharmacological family	alpha conotoxin

Sequence

GCCSDPRCRYRCR
Sequence evidence	nucleic acid level
Average Mass	1570.79
Monoisotopic Mass	1569.62
Isoelectric Point	12.50
Extinction Coefficient [280nm]	1490.00

Activity

IC50: Nicotinic acetylcholine receptors

Target	Organism		IC50		n_hill	Agonist	Ref
α1β1δε	H. sapiens		16uM			10uM Ach	Vincler,M. et al. (2006)
α2β2	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α2β4	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α3β2	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α3β4	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α4β2	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α4β4	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α6/α3β2β3	R. norvegicus		>10uM			100 uM Ach	Ellison,M. et al. (2006)
α6/α3β4	R. norvegicus		>10uM			100 uM Ach	Vincler,M. et al. (2006)
α7	R. norvegicus		4.66uM		1.2	200 uM Ach	Ellison,M. et al. (2006)
			3.31uM		0.9	200uM Ach	Ellison,M. et al. (2008)
α9α10	H. sapiens		1400nM	[1000-1960]	0.51		Ren et al. (2019)
			510 nM	[303-856]		100 uM Ach	Huynh,P.N. et al. (2020)
			510 nM	[303-856]		100 uM Ach	Zheng N et al. (2021)
			>10000 nM			10 uM ACh	Romero,H.K. et al. (2017)
	R. norvegicus	(minus BAPTA)	3.60nM		0.98	10uM Ach	Ellison,M. et al. (2006)
		(plus BAPTA)	5.19nM		1.2	10uM Ach	Ellison,M. et al. (2006)
			5.2nM			10uM Ach	Vincler,M. et al. (2006)
			2.4 nM	+/-0.7	0.67	10 uM ACh	Romero,H.K. et al. (2017)
			2.6nM	[2.1-3.22]	0.8		Ren et al. (2019)
			4.55nM		1.1	10uM Ach	Ellison,M. et al. (2006)
			8.47nM		1.3	50uM Ach	Ellison,M. et al. (2008)
			1.8 nM	[1.4-2.2]		100 uM Ach	Huynh,P.N. et al. (2020)
	unidentified	(nAChR was hybrid human ?9/rat ?10)	40 nM	[28-59]		50 nM	Halai,R. et al. (2011)

Percentage inhibition: Nicotinic acetylcholine receptors

Target	Organism		% inhibition		Concentration	Ref
α9α10	H. sapiens		10	+/-2.5	10 nM	Huynh,P.N. et al. (2020)
	unidentified	(nAChR was hybrid human ?9/rat ?10. )	60	+/-4	50 nM	Halai,R. et al. (2011)

Synthetic variants

Cy3-RgIA-5727	(Cy3Trz)GC(Pen)TDPRCR(Ity)QC(β3hY)R
RgIA [C12c]	GCCSDPRCRYRcR
RgIA [C2(Pen),S4T,R9(Cit),Y10(Ity),R11Q,R13Y]	G(Pen)CTDPRC(Cit)(Ity)QCY
RgIA [C2(Smc),C3(Smc),S4T,R9(Cit),Y10(Ity),R11Q,R13Y]	G(Smc)(Smc)TDPRC(Cit)(Ity)QCY
RgIA [C2(Smc),S4T,C8,R9(Cit),Y10(Ity),R11Q,R13Y]	G(Smc)CTDPRC(Cit)(Ity)QCY
RgIA [C2c]	GcCSDPRCRYRCR
RgIA [C3(Pen),S4T,R9(Cit),Y10(Ity),R11Q,C12(Pen),R13Y]	GC(Pen)TDPRC(Cit)(Ity)Q(Pen)Y
RgIA [C3(Pen),S4T,R9(Cit),Y10(Ity),R11Q,R13Y]	GC(Pen)TDPRC(Cit)(Ity)QCY
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13(β3hY),insC_(Cit)]	GC(Pen)TDPRCR(Ity)QC(β3hY)(Cit)
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13(β3hY),insC_(Orn)]	GC(Pen)TDPRCR(Ity)QC(β3hY)(Orn)
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13(β3hY),insC_E]	GC(Pen)TDPRCR(Ity)QC(β3hY)E
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13(β3hY),insC_K]	GC(Pen)TDPRCR(Ity)QC(β3hY)K
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13(β3hY),insC_R]	GC(Pen)TDPRCR(Ity)QC(β3hY)R
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13(β3hY),insC_r]	GC(Pen)TDPRCR(Ity)QC(β3hY)r
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13Y,insC_R]	GC(Pen)TDPRCR(Ity)QCYR
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13Y]	GC(Pen)TDPRCR(Ity)QCY
RgIA [C3(Pen),S4T,Y10(Ity),R11Q,R13y,insC_r]	GC(Pen)TDPRCR(Ity)QCyr
RgIA [C3(Smc),S4T,R9(Cit),Y10(Ity),R11Q,R13Y]	GC(Smc)TDPRC(Cit)(Ity)QCY
RgIA [C3(Smc),S4T,Y10(Ity),R11Q,ins13(bA)]	GC(Smc)TDPRCR(Ity)QC(bA)R
RgIA [C3(Smc),S4T,Y10(Ity),R11Q,ins13(bhY)]	GC(Smc)TDPRCR(Ity)QC(bhY)R
RgIA [C3c]	GCcSDPRCRYRCR
RgIA [C8c]	GCCSDPRcRYRCR
RgIA [Cys2Agl,Cys8Agl]	G(Agl)CSDPR(Agl)RYRCR
RgIA [Cys3Agl,Cys12Agl]	GC(Agl)SDPRCRYR(Agl)R
RgIA [D5E]	GCCSEPRCRYRCR
RgIA [D5d]	GCCSdPRCRYRCR
RgIA [G1a]	aCCSDPRCRYRCR
RgIA [P6V]	GCCSDVRCRYRCR
RgIA [P6p]	GCCSDpRCRYRCR
RgIA [R11Cit]	GCCSDPRCRY(Cit)CR
RgIA [R11K]	GCCSDPRCRYKCR
RgIA [R11Nar]	GCCSDPRCRY(Nar)CR
RgIA [R11Q]	GCCSDPRCRYQCR
RgIA [R11hArg]	GCCSDPRCRY(hArg)CR
RgIA [R11r]	GCCSDPRCRYrCR
RgIA [R13COOH-Phe] amidated	GCCSDPRCRYRC(COOH-Phe)(nh2)
RgIA [R13Cit]	GCCSDPRCRYRC(Cit)
RgIA [R13F]	GCCSDPRCRYRCF
RgIA [R13F] amidated	GCCSDPRCRYRCF(nh2)
RgIA [R13K]	GCCSDPRCRYRCK
RgIA [R13W]	GCCSDPRCRYRCW
RgIA [R13Y]	GCCSDPRCRYRCY
RgIA [R13Y] amidated	GCCSDPRCRYRCR(nh2)
RgIA [R13r]	GCCSDPRCRYRCr
RgIA [R7Cit]	GCCSDP(Cit)CRYRCR
RgIA [R7K]	GCCSDPKCRYRCR
RgIA [R7Nar]	GCCSDP(Nar)CRYRCR
RgIA [R7hArg]	GCCSDP(hArg)CRYRCR
RgIA [R7r,R9r,R11r,R13r]	GCCSDPrCrYrCr
RgIA [R7r,R9r,R11r,del13] amidated	GCCSDPrCrYrC(nh2)
RgIA [R7r]	GCCSDPrCRYRCR
RgIA [R9A]	GCCSDPRCAYRCR
RgIA [R9Cit]	GCCSDPRC(Cit)YRCR
RgIA [R9K]	GCCSDPRCKYRCR
RgIA [R9Nar]	GCCSDPRC(Nar)YRCR
RgIA [R9hArg]	GCCSDPRC(hArg)YRCR
RgIA [R9r]	GCCSDPRCrYRCR
RgIA [S4A]	GCCADPRCRYRCR
RgIA [S4T,C2(Pen),C8(Pen),R9(Cit),Y10(Ity),R11Q,R13Y]	G(Pen)CTDPR(Pen)(Cit)(Ity)QCY
RgIA [S4T,C8(Pen),R9(Cit),Y10(Ity),R11Q,R13Y]	GCCTDPR(Pen)(Cit)(Ity)QCY
RgIA [S4T,R9(Cit),Y10(Ity),R11Q,C12(Pen),R13Y]	GCCTDPRC(Cit)(Ity)Q(Pen)Y
RgIA [S4T,R9(Cit),Y10(Ity),R11Q,R13Y]	GCCTDPRC(Cit)(Ity)QCY
RgIA [S4T,Y10(Ity),R11Q,R13Y]	GCCTDPRCR(Ity)QCY
RgIA [S4s]	GCCsDPRCRYRCR
RgIA [Y10Iyr]	GCCSDPRCR(Ity)RCR
RgIA [Y10W]	GCCSDPRCRWRCR
RgIA [Y10y]	GCCSDPRCRyRCR
RgIA [del13,insC_GAAGG] cyclic	GCCSDPRCRYRCGAAGG
RgIA [del13,insC_GAAG] cyclic	GCCSDPRCRYRCGAAG
RgIA [del13,insC_GAA] cyclic	GCCSDPRCRYRCGAA
RgIA [del13,insC_GGAAGAG] cyclic	GCCSDPRCRYRCGGAAGAG
RgIA [del13,insC_GGAAGG] cyclic	GCCSDPRCRYRCGGAAGG
RgIA [del13]	GCCSDPRCRYRC(nh2)
RgIA[R9(Cit),Y10(Ity)]	GCCSDPRC(Cit)(Ity)RCR
RgIA[S4T,R9(Cit),Y10(Ity),R11Q,insC_RR]	GCCTDPRC(Cit)(Ity)QCRRR
RgIA[S4T,R9(Cit),Y10(Ity),R11Q]	GCCTDPRC(Cit)(Ity)QCR
RgIA[Y10(Ity)]	GCCSDPRCR(Ity)RCR

References

Ellison,M., Haberlandt,C., Gomez-Casati,M.E., Watkins,M., Elgoyhen,A.B., McIntosh,J.M. and Olivera,B.M. (2006) Alpha-RgIA: a novel conotoxin that specifically and potently blocks the alpha9alpha10 nAChR Biochemistry 45:1511-1517

Ellison,M., Feng,Z.P., Park,A.J., Zhang,X., Olivera,B.M., McIntosh,J.M. and Norton,R.S. (2008) Alpha-RgIA, a novel conotoxin that blocks the alpha9alpha10 nAChR: structure and identification of key receptor-binding residues. J. Mol. Biol. 377:1216-1227

Cuny,H., Kompella,S.N., Tae,H.S., Yu,R. and Adams,D.J. (2016) Key Structural Determinants in the Agonist Binding Loops of Human β2 and β4 Nicotinic Acetylcholine Receptor Subunits Contribute to α3β4 Subtype Selectivity of α-Conotoxins. J. Biol. Chem. 291:23779-23792

Callaghan,B., Haythornthwaite,A., Berecki,G., Clark,R.J., Craik,D.J. and Adams,D.J. (2008) Analgesic alpha-conotoxins Vc1.1 and Rg1A inhibit N-type calcium channels in rat sensory neurons via GABAB receptor activation. J. Neurosci. 28:10943-10951

Halai,R., Callaghan,B., Daly,N.L., Clark,R.J., Adams,D.J. and Craik,D.J. (2011) Effects of cyclization on stability, structure, and activity of α-conotoxin RgIA at the α9α10 nicotinic acetylcholine receptor and GABA(B) receptor. J. Med. Chem. 54:6984-6992

Ren, J., Zhu, X., Xu, P., Li, R., Fu, Y., Dong, S., Zhangsun, D., Wu, Y. and Luo, S. (2019) d-Amino Acid Substitution of α-Conotoxin RgIA Identifies its Critical Residues and Improves the Enzymatic Stability Marine drugs 17:142

AlSharari,S.D., Toma,W., Mahmood,H.M., Michael McIntosh,J. and Imad Damaj,M. (2020) The α9α10 nicotinic acetylcholine receptors antagonist α-conotoxin RgIA reverses colitis signs in murine dextran sodium sulfate model Eur. J. Pharmacol. 173320

Huynh,P.N., Harvey,P.J., Gajewiak,J., Craik,D.J. and Michael McIntosh,J. (2020) Critical residue properties for potency and selectivity of α-Conotoxin RgIA towards α9α10 nicotinic acetylcholine receptors. Biochem. Pharmacol. :114124

Callaghan,B. and Adams,D.J. (2010) Analgesic α-conotoxins Vc1.1 and RgIA inhibit N-type calcium channels in sensory neurons of α9 nicotinic receptor knockout mice. Channels (Austin) 4:51-54

Terpinskaya,T.I., Osipov,A.V., Kryukova,E.V., Kudryavtsev,D.S., Kopylova,N.V., Yanchanka,T.L., Palukoshka,A.F., Gondarenko,E.A., Zhmak,M.N., Tsetlin,V.I. and Utkin,Y.N. (2021) α-Conotoxins and α-Cobratoxin Promote, while Lipoxygenase and Cyclooxygenase Inhibitors Suppress the Proliferation of Glioma C6 Cells. Mar Drugs 19

Romero,H.K., Christensen,S.B., Di Cesare Mannelli,L., Gajewiak,J., Ramachandra,R., Elmslie,K.S., Vetter,D.E., Ghelardini,C., Iadonato,S.P., Mercado,J.L., Olivera,B.M. and McIntosh,J.M. (2017) Inhibition of α9α10 nicotinic acetylcholine receptors prevents chemotherapy-induced neuropathic pain. Proc Natl Acad Sci U S A 114

Zheng N, Christensen SB, Dowell C, Purushottam L, Skalicky JJ, McIntosh JM, Chou DH. (2021) Discovery of Methylene Thioacetal-Incorporated α-RgIA Analogues as Potent and Stable Antagonists of the Human α9β10 Nicotinic Acetylcholine Receptor for the Treatment of Neuropathic Pain J Med Chem 64:9513-9524

Pan,S., Fan,Y., Zhu,X., Xue,Y., Luo,S., Wang,X. (2021) From Crystal Structures of RgIA4 in Complex with Ac-AChBP to Molecular Determinants of Its High Potency of α9α10 nAChR. Mar Drugs 19:709

Bony,A.R., McArthur,J.R., Finol-Urdaneta,R.K., and Adams,D.J. (2022) Analgesic α-conotoxins modulate native and recombinant GIRK1/2 channels via activation of GABAB receptors and reduce neuroexcitability. Br J Pharmacol 179:179-198

Internal links

Protein Precursor	RgIA precursor (593)
Nucleic acids
Structure	alpha-RgIA, a Novel Conotoxin That Blocks the alpha9alpha10 nAChR Solution structure of RgIA Co-crystal structure of Ac-AChBPP in complex with RgIA

External links

Ncbi

ABB55879, P0C1D0

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