Mutagenetix > Incidental Mutation

Incidental Mutation 'N/A:Cacna1s'

Institutional Source

Beutler Lab

Gene Symbol

Cacna1s

Ensembl Gene

ENSMUSG00000026407

Gene Name

calcium channel, voltage-dependent, L type, alpha 1S subunit

Synonyms

mdg, muscle dysgenesis, sj, Cav1.1, Cchl1a3, DHPR alpha1s, fmd

Accession Numbers

Essential gene?

Essential (E-score: 1.000) question?

Stock #

N/A of strain 294

Quality Score

Status

Validated

Chromosome

Chromosomal Location

135980549-136047268 bp(+) (GRCm39)

Type of Mutation

missense

DNA Base Change (assembly)

A to G at 136001247 bp (GRCm39)

Zygosity

Homozygous

Amino Acid Change

Isoleucine to Valine at position 233 (I233V)

Ref Sequence

ENSEMBL: ENSMUSP00000125278 (fasta)

Gene Model

predicted gene model for transcript(s): [ENSMUST00000112064] [ENSMUST00000112068] [ENSMUST00000160641] [ENSMUST00000161865]

AlphaFold

no structure available at present

Predicted Effect

probably benign
Transcript: ENSMUST00000112064
AA Change: I233V

PolyPhen 2 Score 0.003 (Sensitivity: 0.98; Specificity: 0.44)

SMART Domains

Protein: ENSMUSP00000107695
Gene: ENSMUSG00000026407
AA Change: I233V

Domain	Start	End	E-Value	Type
Pfam:Ion_trans	50	345	4.3e-68	PFAM
Pfam:Ion_trans	431	672	4.5e-56	PFAM
Pfam:PKD_channel	516	667	1.9e-7	PFAM
low complexity region	675	685	N/A	INTRINSIC
low complexity region	740	756	N/A	INTRINSIC
Pfam:Ion_trans	798	1076	2.6e-65	PFAM
Pfam:Ion_trans	1117	1392	1.2e-71	PFAM
Pfam:PKD_channel	1126	1387	8.4e-13	PFAM
Pfam:GPHH	1394	1463	2.3e-38	PFAM
Ca_chan_IQ	1515	1548	3.71e-14	SMART
low complexity region	1657	1669	N/A	INTRINSIC
Pfam:CAC1F_C	1756	1845	2.8e-8	PFAM

Predicted Effect

probably benign
Transcript: ENSMUST00000112068
AA Change: I233V

PolyPhen 2 Score 0.003 (Sensitivity: 0.98; Specificity: 0.44)

SMART Domains

Protein: ENSMUSP00000107699
Gene: ENSMUSG00000026407
AA Change: I233V

Domain	Start	End	E-Value	Type
Pfam:Ion_trans	88	333	9.1e-57	PFAM
PDB:4DEY\|B	334	417	1e-20	PDB
Pfam:Ion_trans	466	660	3.7e-46	PFAM
Pfam:PKD_channel	513	667	6.7e-7	PFAM
low complexity region	675	685	N/A	INTRINSIC
low complexity region	740	756	N/A	INTRINSIC
low complexity region	804	818	N/A	INTRINSIC
Pfam:Ion_trans	834	1064	3.9e-53	PFAM
Pfam:Ion_trans	1152	1361	6.7e-66	PFAM
Pfam:PKD_channel	1201	1368	8.4e-10	PFAM
Blast:EFh	1382	1410	5e-8	BLAST
Ca_chan_IQ	1496	1529	3.71e-14	SMART
low complexity region	1638	1650	N/A	INTRINSIC

Predicted Effect

probably benign
Transcript: ENSMUST00000160641
AA Change: I233V

PolyPhen 2 Score 0.003 (Sensitivity: 0.98; Specificity: 0.44)

SMART Domains

Protein: ENSMUSP00000125278
Gene: ENSMUSG00000026407
AA Change: I233V

Domain	Start	End	E-Value	Type
Pfam:Ion_trans	88	333	9.3e-57	PFAM
PDB:4DEY\|B	334	417	1e-20	PDB
Pfam:Ion_trans	466	660	3.8e-46	PFAM
Pfam:PKD_channel	513	667	6.7e-7	PFAM
low complexity region	675	685	N/A	INTRINSIC
low complexity region	740	756	N/A	INTRINSIC
low complexity region	804	818	N/A	INTRINSIC
Pfam:Ion_trans	834	1064	4e-53	PFAM
Pfam:PKD_channel	1126	1387	6.1e-12	PFAM
Pfam:Ion_trans	1152	1380	9e-65	PFAM
Blast:EFh	1401	1429	5e-8	BLAST
Ca_chan_IQ	1515	1548	3.71e-14	SMART
low complexity region	1657	1669	N/A	INTRINSIC

Predicted Effect

probably benign
Transcript: ENSMUST00000161865

SMART Domains

Protein: ENSMUSP00000125262
Gene: ENSMUSG00000026407

Domain	Start	End	E-Value	Type
Pfam:Ion_trans	3	98	1.1e-21	PFAM
Pfam:Ion_trans	184	425	3.3e-56	PFAM
Pfam:PKD_channel	267	420	1.8e-7	PFAM
low complexity region	428	438	N/A	INTRINSIC
low complexity region	493	509	N/A	INTRINSIC
Pfam:Ion_trans	551	829	1.9e-65	PFAM
Pfam:Ion_trans	870	1126	5.4e-72	PFAM
Pfam:PKD_channel	954	1121	7.2e-10	PFAM
Pfam:GPHH	1128	1197	1.8e-38	PFAM
Ca_chan_IQ	1249	1282	3.71e-14	SMART
low complexity region	1391	1403	N/A	INTRINSIC

Meta Mutation Damage Score

0.0825

Coding Region Coverage

1x: 88.7%
3x: 76.0%

Validation Efficiency

91% (106/116)

MGI Phenotype

FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes one of the five subunits of the slowly inactivating L-type voltage-dependent calcium channel in skeletal muscle cells. Mutations in this gene have been associated with hypokalemic periodic paralysis, thyrotoxic periodic paralysis and malignant hyperthermia susceptibility. [provided by RefSeq, Jul 2008]
PHENOTYPE: Homozygous mutants show edema and failure of myoblast differentiation by day 13 of embryonic development and die perinatally. All muscles degenerate and additional secondary anomalies of the skeleton, short jaw, and cleft palate are seen. [provided by MGI curators]

Allele List at MGI

All alleles(4) : Targeted(3) Spontaneous(1)

Other mutations in this stock

Total: 18 list
Gene	Ref	Var	Chr/Loc	Mutation	Predicted Effect	Zygosity
1700016P04Rik	T	A	6: 13,415,772 (GRCm39)		noncoding transcript	Homo
Aif1	A	G	17: 35,391,496 (GRCm39)	L7S	possibly damaging	Homo
Ankrd26	T	C	6: 118,506,535 (GRCm39)	D646G	probably benign	Homo
Cfap92	A	T	6: 87,667,773 (GRCm39)		noncoding transcript	Homo
Chchd4	T	C	6: 91,442,187 (GRCm39)	Y77C	probably damaging	Homo
Crocc	G	A	4: 140,749,057 (GRCm39)	R1419C	probably damaging	Homo
Cyp4f39	A	C	17: 32,687,655 (GRCm39)	M74L	probably benign	Homo
Fgf9	C	A	14: 58,327,421 (GRCm39)		probably benign	Homo
Gimap6	T	C	6: 48,679,349 (GRCm39)	D229G	probably damaging	Homo
Glp1r	T	C	17: 31,150,257 (GRCm39)	F393S	probably damaging	Homo
Lrrc7	T	G	3: 157,865,977 (GRCm39)	I1255L	probably benign	Homo
Mtrr	C	A	13: 68,723,516 (GRCm39)		probably benign	Homo
Pde6b	A	T	5: 108,576,969 (GRCm39)		probably benign	Homo
Rbm19	A	T	5: 120,282,162 (GRCm39)	I840F	probably damaging	Homo
Serpina3c	A	C	12: 104,115,864 (GRCm39)	S227A	probably benign	Homo
Spag17	G	A	3: 99,889,570 (GRCm39)		probably benign	Homo
Spmip3	G	A	1: 177,561,100 (GRCm39)	R13H	probably damaging	Homo
Zbtb8b	T	C	4: 129,326,361 (GRCm39)	D268G	probably benign	Homo

Other mutations in Cacna1s

Allele	Source	Chr	Coord	Type	Predicted Effect	PPH Score
IGL00336:Cacna1s	APN	1	136,012,011 (GRCm39)	nonsense	probably null
IGL00517:Cacna1s	APN	1	136,015,077 (GRCm39)	missense	probably damaging	1.00
IGL01316:Cacna1s	APN	1	136,046,702 (GRCm39)	missense	probably benign	0.01
IGL01348:Cacna1s	APN	1	136,002,890 (GRCm39)	missense	possibly damaging	0.95
IGL01739:Cacna1s	APN	1	136,024,870 (GRCm39)	critical splice donor site	probably null
IGL01773:Cacna1s	APN	1	136,046,491 (GRCm39)	missense	probably benign	0.32
IGL02056:Cacna1s	APN	1	136,046,738 (GRCm39)	missense	probably benign
IGL02262:Cacna1s	APN	1	136,035,867 (GRCm39)	missense	probably damaging	0.98
IGL02324:Cacna1s	APN	1	136,002,914 (GRCm39)	splice site	probably benign
IGL02352:Cacna1s	APN	1	136,020,990 (GRCm39)	splice site	probably benign
IGL02359:Cacna1s	APN	1	136,020,990 (GRCm39)	splice site	probably benign
IGL02370:Cacna1s	APN	1	136,013,085 (GRCm39)	missense	probably damaging	1.00
IGL02377:Cacna1s	APN	1	135,996,732 (GRCm39)	missense	probably damaging	1.00
IGL02474:Cacna1s	APN	1	136,046,118 (GRCm39)	missense	probably benign
IGL02606:Cacna1s	APN	1	136,007,257 (GRCm39)	missense	probably damaging	0.99
IGL02833:Cacna1s	APN	1	135,998,743 (GRCm39)	missense	probably benign	0.03
IGL02974:Cacna1s	APN	1	136,020,355 (GRCm39)	missense	possibly damaging	0.78
IGL03064:Cacna1s	APN	1	136,039,731 (GRCm39)	missense	probably damaging	1.00
IGL03093:Cacna1s	APN	1	136,043,802 (GRCm39)	missense	probably benign	0.00
IGL03286:Cacna1s	APN	1	136,005,397 (GRCm39)	missense	probably benign
brookstone	UTSW	1	136,020,432 (GRCm39)	missense	probably benign	0.01
flyfish	UTSW	1	136,043,799 (GRCm39)	missense	probably benign	0.21
forelle	UTSW	1	136,023,596 (GRCm39)	missense	probably damaging	0.99
river	UTSW	1	136,033,582 (GRCm39)	missense	possibly damaging	0.88
stream	UTSW	1	136,033,552 (GRCm39)	missense	probably damaging	1.00
BB009:Cacna1s	UTSW	1	136,012,097 (GRCm39)	missense	probably damaging	0.99
BB019:Cacna1s	UTSW	1	136,012,097 (GRCm39)	missense	probably damaging	0.99
G1Funyon:Cacna1s	UTSW	1	136,001,179 (GRCm39)	unclassified	probably benign
R0030:Cacna1s	UTSW	1	136,022,727 (GRCm39)	critical splice donor site	probably null
R0030:Cacna1s	UTSW	1	136,022,727 (GRCm39)	critical splice donor site	probably null
R0097:Cacna1s	UTSW	1	136,028,360 (GRCm39)	missense	possibly damaging	0.79
R0097:Cacna1s	UTSW	1	136,028,360 (GRCm39)	missense	possibly damaging	0.79
R0240:Cacna1s	UTSW	1	136,001,234 (GRCm39)	unclassified	probably benign
R0255:Cacna1s	UTSW	1	136,046,544 (GRCm39)	missense	possibly damaging	0.93
R0302:Cacna1s	UTSW	1	136,028,342 (GRCm39)	missense	probably benign	0.01
R0319:Cacna1s	UTSW	1	135,998,455 (GRCm39)	missense	probably damaging	0.99
R0411:Cacna1s	UTSW	1	136,041,041 (GRCm39)	missense	probably damaging	1.00
R0413:Cacna1s	UTSW	1	136,025,947 (GRCm39)	missense	probably benign	0.00
R0482:Cacna1s	UTSW	1	136,041,132 (GRCm39)	missense	probably benign
R0491:Cacna1s	UTSW	1	136,016,746 (GRCm39)	splice site	probably benign
R0518:Cacna1s	UTSW	1	136,004,597 (GRCm39)	missense	probably benign
R0717:Cacna1s	UTSW	1	136,026,029 (GRCm39)	missense	probably damaging	1.00
R0725:Cacna1s	UTSW	1	136,026,264 (GRCm39)	splice site	probably benign
R0815:Cacna1s	UTSW	1	136,040,695 (GRCm39)	missense	possibly damaging	0.95
R1384:Cacna1s	UTSW	1	136,022,709 (GRCm39)	missense	probably benign	0.02
R1518:Cacna1s	UTSW	1	136,026,289 (GRCm39)	missense	probably damaging	1.00
R1548:Cacna1s	UTSW	1	136,038,675 (GRCm39)	missense	probably damaging	1.00
R1725:Cacna1s	UTSW	1	136,026,361 (GRCm39)	missense	probably damaging	1.00
R1728:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1729:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1730:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1739:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1762:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1783:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1784:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1785:Cacna1s	UTSW	1	136,046,454 (GRCm39)	missense	probably benign
R1800:Cacna1s	UTSW	1	136,004,592 (GRCm39)	missense	probably benign
R1924:Cacna1s	UTSW	1	136,016,755 (GRCm39)	splice site	probably null
R1969:Cacna1s	UTSW	1	136,046,833 (GRCm39)	missense	probably benign	0.42
R2072:Cacna1s	UTSW	1	136,007,242 (GRCm39)	missense	probably benign
R2380:Cacna1s	UTSW	1	136,023,586 (GRCm39)	missense	probably damaging	1.00
R3110:Cacna1s	UTSW	1	136,002,831 (GRCm39)	nonsense	probably null
R3112:Cacna1s	UTSW	1	136,002,831 (GRCm39)	nonsense	probably null
R3151:Cacna1s	UTSW	1	136,033,532 (GRCm39)	missense	probably damaging	1.00
R3696:Cacna1s	UTSW	1	136,033,552 (GRCm39)	missense	probably damaging	1.00
R3722:Cacna1s	UTSW	1	135,996,780 (GRCm39)	missense	possibly damaging	0.77
R3804:Cacna1s	UTSW	1	136,034,756 (GRCm39)	missense	possibly damaging	0.85
R3813:Cacna1s	UTSW	1	136,013,085 (GRCm39)	missense	probably damaging	1.00
R3905:Cacna1s	UTSW	1	136,012,007 (GRCm39)	missense	probably damaging	0.99
R3907:Cacna1s	UTSW	1	136,012,007 (GRCm39)	missense	probably damaging	0.99
R3909:Cacna1s	UTSW	1	136,012,007 (GRCm39)	missense	probably damaging	0.99
R4170:Cacna1s	UTSW	1	136,035,933 (GRCm39)	missense	probably damaging	1.00
R4329:Cacna1s	UTSW	1	136,046,771 (GRCm39)	missense	probably benign	0.00
R4485:Cacna1s	UTSW	1	136,004,590 (GRCm39)	missense	probably damaging	1.00
R4581:Cacna1s	UTSW	1	135,998,708 (GRCm39)	splice site	probably null
R4719:Cacna1s	UTSW	1	136,046,390 (GRCm39)	splice site	probably benign
R4816:Cacna1s	UTSW	1	136,043,007 (GRCm39)	missense	possibly damaging	0.89
R4909:Cacna1s	UTSW	1	136,007,342 (GRCm39)	missense	probably damaging	0.99
R4917:Cacna1s	UTSW	1	136,029,302 (GRCm39)	critical splice donor site	probably null
R5296:Cacna1s	UTSW	1	136,023,523 (GRCm39)	missense	probably benign	0.11
R5411:Cacna1s	UTSW	1	136,033,549 (GRCm39)	missense	probably benign	0.09
R5503:Cacna1s	UTSW	1	136,014,480 (GRCm39)	missense	probably damaging	1.00
R5533:Cacna1s	UTSW	1	136,026,113 (GRCm39)	critical splice donor site	probably null
R5714:Cacna1s	UTSW	1	136,039,804 (GRCm39)	missense	probably benign	0.44
R5775:Cacna1s	UTSW	1	136,035,860 (GRCm39)	missense	probably damaging	1.00
R5814:Cacna1s	UTSW	1	136,034,880 (GRCm39)	missense	probably benign	0.31
R5820:Cacna1s	UTSW	1	136,007,342 (GRCm39)	missense	probably damaging	1.00
R5822:Cacna1s	UTSW	1	136,039,816 (GRCm39)	missense	probably damaging	1.00
R5877:Cacna1s	UTSW	1	136,028,405 (GRCm39)	missense	probably damaging	0.99
R5923:Cacna1s	UTSW	1	136,004,560 (GRCm39)	missense	possibly damaging	0.79
R6021:Cacna1s	UTSW	1	136,034,225 (GRCm39)	missense	probably benign	0.15
R6037:Cacna1s	UTSW	1	135,998,705 (GRCm39)	missense	possibly damaging	0.90
R6037:Cacna1s	UTSW	1	135,998,705 (GRCm39)	missense	possibly damaging	0.90
R6056:Cacna1s	UTSW	1	136,033,574 (GRCm39)	missense	probably damaging	1.00
R6143:Cacna1s	UTSW	1	136,004,496 (GRCm39)	missense	probably damaging	0.99
R6222:Cacna1s	UTSW	1	136,032,360 (GRCm39)	missense	probably benign	0.00
R6237:Cacna1s	UTSW	1	136,033,582 (GRCm39)	missense	possibly damaging	0.88
R6274:Cacna1s	UTSW	1	136,016,783 (GRCm39)	missense	probably benign	0.02
R6609:Cacna1s	UTSW	1	136,041,129 (GRCm39)	missense	probably benign	0.30
R6626:Cacna1s	UTSW	1	136,022,703 (GRCm39)	missense	probably damaging	1.00
R6838:Cacna1s	UTSW	1	136,012,175 (GRCm39)	missense	possibly damaging	0.91
R6848:Cacna1s	UTSW	1	136,020,432 (GRCm39)	missense	probably benign	0.01
R6849:Cacna1s	UTSW	1	136,020,432 (GRCm39)	missense	probably benign	0.01
R6850:Cacna1s	UTSW	1	136,020,432 (GRCm39)	missense	probably benign	0.01
R6851:Cacna1s	UTSW	1	136,020,432 (GRCm39)	missense	probably benign	0.01
R6868:Cacna1s	UTSW	1	136,020,432 (GRCm39)	missense	probably benign	0.01
R6879:Cacna1s	UTSW	1	136,043,697 (GRCm39)	missense	probably benign	0.12
R6893:Cacna1s	UTSW	1	136,005,431 (GRCm39)	missense	probably benign	0.05
R7017:Cacna1s	UTSW	1	136,023,596 (GRCm39)	missense	probably damaging	0.99
R7228:Cacna1s	UTSW	1	135,998,797 (GRCm39)	missense	possibly damaging	0.90
R7283:Cacna1s	UTSW	1	136,001,446 (GRCm39)	missense	probably damaging	1.00
R7357:Cacna1s	UTSW	1	135,998,759 (GRCm39)	missense	probably damaging	0.99
R7385:Cacna1s	UTSW	1	136,020,371 (GRCm39)	missense	probably damaging	0.99
R7421:Cacna1s	UTSW	1	136,014,540 (GRCm39)	missense	probably damaging	1.00
R7505:Cacna1s	UTSW	1	136,013,187 (GRCm39)	nonsense	probably null
R7519:Cacna1s	UTSW	1	135,998,494 (GRCm39)	missense	probably damaging	0.99
R7675:Cacna1s	UTSW	1	136,038,612 (GRCm39)	missense	probably damaging	1.00
R7746:Cacna1s	UTSW	1	135,996,756 (GRCm39)	missense	probably damaging	0.99
R7779:Cacna1s	UTSW	1	136,046,767 (GRCm39)	missense	probably damaging	1.00
R7850:Cacna1s	UTSW	1	135,998,786 (GRCm39)	missense	probably damaging	1.00
R7932:Cacna1s	UTSW	1	136,012,097 (GRCm39)	missense	probably damaging	0.99
R7935:Cacna1s	UTSW	1	136,020,333 (GRCm39)	missense	possibly damaging	0.62
R7950:Cacna1s	UTSW	1	136,028,363 (GRCm39)	missense	probably benign	0.01
R7969:Cacna1s	UTSW	1	136,004,470 (GRCm39)	missense	probably damaging	1.00
R8083:Cacna1s	UTSW	1	136,023,529 (GRCm39)	missense	possibly damaging	0.91
R8101:Cacna1s	UTSW	1	136,046,403 (GRCm39)	missense	probably benign	0.02
R8123:Cacna1s	UTSW	1	136,035,917 (GRCm39)	missense	probably damaging	1.00
R8191:Cacna1s	UTSW	1	136,035,893 (GRCm39)	missense	probably damaging	1.00
R8194:Cacna1s	UTSW	1	136,005,430 (GRCm39)	missense	probably benign	0.33
R8251:Cacna1s	UTSW	1	136,014,461 (GRCm39)	missense	probably damaging	1.00
R8265:Cacna1s	UTSW	1	136,020,364 (GRCm39)	nonsense	probably null
R8301:Cacna1s	UTSW	1	136,001,179 (GRCm39)	unclassified	probably benign
R8310:Cacna1s	UTSW	1	136,015,075 (GRCm39)	missense	probably damaging	1.00
R8359:Cacna1s	UTSW	1	136,043,799 (GRCm39)	missense	probably benign	0.21
R8461:Cacna1s	UTSW	1	136,001,440 (GRCm39)	missense	possibly damaging	0.53
R8553:Cacna1s	UTSW	1	136,019,540 (GRCm39)	missense	possibly damaging	0.93
R8743:Cacna1s	UTSW	1	136,033,286 (GRCm39)	missense	probably damaging	1.00
R8766:Cacna1s	UTSW	1	136,002,881 (GRCm39)	missense	probably damaging	1.00
R8884:Cacna1s	UTSW	1	136,042,981 (GRCm39)	missense	probably benign	0.05
R8897:Cacna1s	UTSW	1	136,045,392 (GRCm39)	missense	probably benign	0.01
R8939:Cacna1s	UTSW	1	136,014,544 (GRCm39)	critical splice donor site	probably null
R8953:Cacna1s	UTSW	1	136,025,170 (GRCm39)	missense	possibly damaging	0.94
R9039:Cacna1s	UTSW	1	136,016,057 (GRCm39)	missense	probably benign
R9058:Cacna1s	UTSW	1	135,998,436 (GRCm39)	nonsense	probably null
R9137:Cacna1s	UTSW	1	135,996,744 (GRCm39)	missense	possibly damaging	0.89
R9332:Cacna1s	UTSW	1	136,020,452 (GRCm39)	nonsense	probably null
R9416:Cacna1s	UTSW	1	136,022,689 (GRCm39)	missense	possibly damaging	0.88
R9427:Cacna1s	UTSW	1	136,012,090 (GRCm39)	missense	probably benign	0.30
R9446:Cacna1s	UTSW	1	136,045,362 (GRCm39)	missense	probably benign	0.00
R9564:Cacna1s	UTSW	1	136,046,516 (GRCm39)	missense	probably benign
R9620:Cacna1s	UTSW	1	136,035,909 (GRCm39)	missense	probably damaging	1.00
X0025:Cacna1s	UTSW	1	136,043,708 (GRCm39)	missense	probably benign	0.00
Z1176:Cacna1s	UTSW	1	136,034,822 (GRCm39)	nonsense	probably null
Z1177:Cacna1s	UTSW	1	136,045,424 (GRCm39)	missense	probably benign	0.00

Nature of Mutation

DNA sequencing using the SOLiD technique identified an A to G transition at position 697 of the Cacna1s transcript (isoform 2, Genbank NM_001081023), in exon 6 of 44 total exons (Figure 1). Multiple isoforms of Cacna1s are displayed in Ensembl.

<--exon 5 exon 6-->

682 TTCATTGGGACAG ACATTGTAGCCACAGTTGAG

228 -F--I--G--T-- D--I--V--A--T--V--E-

The mutated nucleotide is indicated in red lettering, and causes an isoleucine to valine substitution at amino acid 233 of the encoded protein. The mutation has been confirmed by DNA sequencing using the Sanger method (Figure 2).

Protein Function and Prediction

Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The α₁S subunit gives rise to L-type calcium currents. Slowly inactivating or long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group. They are blocked by dihydropyridines (DHP), phenylalkylamines, benzothiazepines, and by ω-agatoxin-IIIA (ω-Aga-IIIA). They are however insensitive to ω-conotoxin-GVIA (ω-CTx-GVIA) and ω-agatoxin-IVA (ω-Aga-IVA). Calcium channels containing the α₁S subunit play an important role in excitation-contraction coupling in skeletal muscle, a process by which electrical signals generated by action potentials at the muscle cell surface are transduced into intracellular release of calcium and ultimately muscle fiber contraction. (from Uniprot Q02789 and OMIM *114208)

Human mutations in Cacna1s result in the diseases malignant hyperthermia (OMIM #145600) and hypokalemic periodic paralysis (OMIM #170400).

The DHP-sensitive L-type Ca²⁺ channel from skeletal muscle is a hetero-oligomeric protein complex composed of five subunits in a 1:1:1:1:1 stoichiometry: two high molecular weight polypeptide subunits (α₁ and α₂) and three smaller units (β, γ, and δ) (1;2). The α₁ subunit determines the characteristic pharmacological and functional properties of the channel for voltage sensing, ion permeability, and drug binding (3). The α₁ subunit encodes 24 transmembrane domains divided into four homologous domains of six transmembrane segments each (subdomains I-IV), similar to the Na⁺ and K⁺ voltage-sensitive channels (Figure 3). TM4 contains the highly conserved positive charges that constitute the voltage sensor.

The I233V mutation is predicted to lie in the extracellular loop between the fifth and sixth transmembrane domains of subdomain I. The mutation is predicted to be benign by the PolyPhen program.

References

1. Catterall, W. A., Seagar, M. J., and Takahashi, M. (1988) Molecular Properties of Dihydropyridine-Sensitive Calcium Channels in Skeletal Muscle. J. Biol. Chem. 263, 3535-3538.

2. Campbell, K. P., Leung, A. T., and Sharp, A. H. (1988) The Biochemistry and Molecular Biology of the Dihydropyridine-Sensitive Calcium Channel. Trends Neurosci. 11, 425-430.

3. Catterall, W. A. (2000) Structure and Regulation of Voltage-Gated Ca2+ Channels. Annu. Rev. Cell Dev. Biol. 16, 521-555.

Posted On

2009-10-27