Reviewed, UniProtKB/Swiss-Prot Q96QZ7 (MAGI1_HUMAN)

Names and origin

Protein names

Recommended name:
    Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1
Alternative name(s):
    BAI1-associated protein 1
      Short name(s)=BAP-1
    Membrane-associated guanylate kinase inverted 1
      Short name(s)=MAGI-1
    Atrophin-1-interacting protein 3
      Short name(s)=AIP3
    WW domain-containing protein 3
      Short name(s)=WWP3
    Trinucleotide repeat-containing gene 19 protein

Gene names

Name:	MAGI1
Synonyms:	BAIAP1, BAP1, TNRC19

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	1491 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	May play a role as scaffolding protein at cell-cell junctions. May regulate acid-induced ACCN3 currents by modulating its expression at the cell surface By similarity.
Subunit structure	Interacts through its WW 2 domain with SYNPO and through its PDZ 5 domain with ACTN4. Interacts with cytoplasmic domain of BAI1. Interacts via its WW domains with DRPLA. Interacts with ESAM, LRP2 and CXADR. May interact with CTNNB1. Interacts through its PDZ 1 domain with NET1 By similarity. Interacts with ACCN3 and AMOT. Interacts with FCHSD2. Interacts with IGSF5/JAM4 and through its PDZ 2 and 3 domains with NPHS1 forming a tripartite complex By similarity.
Subcellular location	Cell junction › tight junction. Cell membrane; Peripheral membrane protein. Note= Localizes to epithelial cells tight junctions.
Tissue specificity	Widely expressed with the exception of skeletal muscle. Isoform 1, isoform 2 and isoform 6 are highly expressed in colon, kidney, lung, liver, and pancreas. Isoform 5 is predominantly expressed in brain and heart. Isoform 3 and isoform 4 are highly expressed in pancreas and brain.
Post-translational modification	Phosphorylated.
Sequence similarities	Contains 1 guanylate kinase-like domain. Contains 6 PDZ (DHR) domains. Contains 2 WW domains.

Ontologies

Keywords
Cellular component	Cell junction Cell membrane Membrane Tight junction
Coding sequence diversity	Alternative splicing
Domain	Repeat
Ligand	ATP-binding Nucleotide-binding
PTM	Phosphoprotein
Technical term	3D-structure
Gene Ontology (GO)
Biological process	cell adhesion Ref.1 Traceable author statement. Source: ProtInc cell surface receptor linked signal transduction Ref.1 Traceable author statement. Source: ProtInc protein complex assembly Ref.1 Non-traceable author statement. Source: ProtInc
Cellular component	intercellular junction Ref.1 Traceable author statement. Source: ProtInc
Molecular function	protein C-terminus binding Ref.1 Traceable author statement. Source: ProtInc
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
ADRB1	P08588	1	EBI-924464,EBI-991009
FCHSD2	O94868	2	EBI-924464,EBI-1215612
KIF1B	O60333-3	1	EBI-924464,EBI-465669

Alternative products

This entry describes 7 isoforms produced by alternative splicing. [Align] [Select]

Notes: Additional isoforms seem to exist.

Isoform 1 (identifier: Q96QZ7-1)

Also known as: MAGI-1C-alpha-beta1;

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Notes: No experimental confirmation available.

Isoform 2 (identifier: Q96QZ7-2)

Also known as: MAGI-1C-beta;

The sequence of this isoform differs from the canonical sequence as follows:
     806-834: PMSPSPASGLSKGEREREINSTNFGECPI → L
     1027-1027: Missing.

Isoform 3 (identifier: Q96QZ7-3)

Also known as: MAGI-1A-alpha-beta1;

The sequence of this isoform differs from the canonical sequence as follows:
     1241-1256: DPSSDRHGPATGPQGV → GGSNYENIPSFPGMTP
     1257-1288: Missing.
     1289-1491: Missing.

Isoform 4 (identifier: Q96QZ7-4)

Also known as: MAGI-1A-alpha;

The sequence of this isoform differs from the canonical sequence as follows:
     806-834: PMSPSPASGLSKGEREREINSTNFGECPI → L
     1027-1027: Missing.
     1028-1038: Missing.
     1039-1094: Missing.
     1241-1256: DPSSDRHGPATGPQGV → GGSNYENIPSFPGMTP
     1257-1288: Missing.
     1289-1491: Missing.

Isoform 5 (identifier: Q96QZ7-5)

Also known as: MAGI-1B-alpha-beta;

The sequence of this isoform differs from the canonical sequence as follows:
     1027-1027: Missing.
     1241-1288: DPSSDRHGPA...LHKSSPHGEK → AMIPPNIAAC...PPPVHKVFRK
     1289-1491: Missing.

Isoform 6 (identifier: Q96QZ7-6)

Also known as: MAGI-1C-beta2;

The sequence of this isoform differs from the canonical sequence as follows:
     806-834: PMSPSPASGLSKGEREREINSTNFGECPI → L
     1027-1027: Missing.
     1028-1038: Missing.

Notes: No experimental confirmation available.

Isoform 7 (identifier: Q96QZ7-7)

Also known as: MAGI-1C-beta3;

The sequence of this isoform differs from the canonical sequence as follows:
     806-834: PMSPSPASGLSKGEREREINSTNFGECPI → L
     1023-1099: GTTFAGNACV...IIPGDESSNA → VMQCQPPSWC...EVQIYSCNNP

Notes: No experimental confirmation available.

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Molecule processing

Chain

1 – 1491

1491

Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1

Regions

Domain

17 – 105

89

PDZ 1

Domain

96 – 287

192

Guanylate kinase-like

Domain

300 – 333

34

WW 1

Domain

359 – 392

34

WW 2

Domain

472 – 554

83

PDZ 2

Domain

643 – 721

79

PDZ 3

Domain

813 – 895

83

PDZ 4

Domain

970 – 1066

97

PDZ 5

Domain

1124 – 1206

83

PDZ 6

Nucleotide binding

103 – 110

8

ATP By similarity

Region

970 – 1066

97

Interaction with FCHSD2

Compositional bias

402 – 421

20

Poly-Gln

Compositional bias

662 – 665

4

Poly-Gly

Compositional bias

978 – 988

11

Poly-Gly

Compositional bias

1341 – 1344

4

Poly-Ala

Compositional bias

1398 – 1401

4

Poly-Arg

Amino acid modifications

Modified residue

866

1

Phosphotyrosine By similarity

Natural variations

Alternative sequence

806 – 834

29

PMSPS…GECPI → L in isoform 2, isoform 4, isoform 6 and isoform 7.

Alternative sequence

1023 – 1099

77

GTTFA…ESSNA → VMQCQPPSWCHSALGGSKHC NSVMGAASLEVQIYSCNNP in isoform 7.

Alternative sequence

1027

1

Missing in isoform 2, isoform 4, isoform 5 and isoform 6.

Alternative sequence

1028 – 1038

11

Missing in isoform 4 and isoform 6.

Alternative sequence

1039 – 1094

56

Missing in isoform 4.

Alternative sequence

1241 – 1288

48

DPSSD…PHGEK → AMIPPNIAACMRNEKLGEAC FYLMGHNQTTTPAATATAPP PVHKVFRK in isoform 5.

Alternative sequence

1241 – 1256

16

DPSSD…GPQGV → GGSNYENIPSFPGMTP in isoform 3 and isoform 4.

Alternative sequence

1257 – 1288

32

Missing in isoform 3 and isoform 4.

Alternative sequence

1289 – 1491

203

Missing in isoform 3, isoform 4 and isoform 5.

Experimental info

Sequence conflict

775

1

A → G in AAC04844. Ref.3

Secondary structure

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1491

Helix Strand Turn

Details...

Beta strand

304 – 310

7

Beta strand

316 – 320

5

Turn

321 – 324

4

Beta strand

325 – 329

5

Turn

331 – 333

3

Beta strand

363 – 369

7

Beta strand

371 – 373

3

Beta strand

375 – 379

5

Turn

380 – 383

4

Beta strand

384 – 388

5

Helix

390 – 398

9

Beta strand

640 – 647

8

Beta strand

652 – 654

3

Beta strand

656 – 659

4

Beta strand

663 – 670

8

Beta strand

685 – 689

5

Helix

699 – 707

9

Beta strand

714 – 721

8

Beta strand

839 – 845

7

Beta strand

853 – 857

5

Beta strand

865 – 870

6

Helix

875 – 879

5

Beta strand

887 – 891

5

Helix

901 – 914

14

Beta strand

916 – 922

7

Beta strand

1150 – 1156

7

Beta strand

1163 – 1168

6

Helix

1170 – 1172

3

Beta strand

1176 – 1181

6

Helix

1186 – 1189

4

Beta strand

1198 – 1202

5

Helix

1212 – 1220

9

Turn

1221 – 1224

4

Beta strand

1225 – 1231

7

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 (MAGI-1C-alpha-beta1) [UniParc]. Last modified September 27, 2004. Version 2. Checksum: 1898962F733CEAC1	FASTA	1,491	164,641
	10 20 30 40 50 60 MSKVIQKKNH WTSRVHECTV KRGPQGELGV TVLGGAEHGE FPYVGAVAAV EAAGLPGGGE 70 80 90 100 110 120 GPRLGEGELL LEVQGVRVSG LPRYDVLGVI DSCKEAVTFK AVRQGGRLNK DLRHFLNQRF 130 140 150 160 170 180 QKGFPDHELQ QTIRDNLYRH AVPCTTRSPR EGEVPGVDYN FLTVKEFLDL EQSGTLLEVG 190 200 210 220 230 240 TYEGNYYGTP KPPSQPVSGK VITTDALHSL QSGSKQSTPK RTKSYNDMQN AGIVHAENEE 250 260 270 280 290 300 EDDVPEMNSS FTADSGEQEE HTLQETALPP VNSSIIAAPI TDPSQKFPQY LPLSAEDNLG 310 320 330 340 350 360 PLPENWEMAY TENGEVYFID HNTKTTSWLD PRCLNKQQKP LEECEDDEGV HTEELDSELE 370 380 390 400 410 420 LPAGWEKIED PVYGIYYVDH INRKTQYENP VLEAKRKKQL EQQQQQQQQQ QQQQQQQQQQ 430 440 450 460 470 480 QTEEWTEDHS ALVPPVIPNH PPSNPEPARE VPLQGKPFFT RNPSELKGKF IHTKLRKSSR 490 500 510 520 530 540 GFGFTVVGGD EPDEFLQIKS LVLDGPAALD GKMETGDVIV SVNDTCVLGH THAQVVKIFQ 550 560 570 580 590 600 SIPIGASVDL ELCRGYPLPF DPDDPNTSLV TSVAILDKEP IIVNGQETYD SPASHSSKTG 610 620 630 640 650 660 KVNGMKDARP SSPADVASNS SHGYPNDTVS LASSIATQPE LITVHIVKGP MGFGFTIADS 670 680 690 700 710 720 PGGGGQRVKQ IVDSPRCRGL KEGDLIVEVN KKNVQALTHN QVVDMLVECP KGSEVTLLVQ 730 740 750 760 770 780 RGGLPVPKKS PKSQPLERKD SQNSSQHSVS SHRSLHTASP SHSTQVLPEF PPAEAQAPDQ 790 800 810 820 830 840 TDSSGQKKPD PFKIWAQSRS MYENRPMSPS PASGLSKGER EREINSTNFG ECPIPDYQEQ 850 860 870 880 890 900 DIFLWRKETG FGFRILGGNE PGEPIYIGHI VPLGAADTDG RLRSGDELIC VDGTPVIGKS 910 920 930 940 950 960 HQLVVQLMQQ AAKQGHVNLT VRRKVVFAVP KTENEVPSPA SSHHSSNQPA SLTEEKRTPQ 970 980 990 1000 1010 1020 GSQNSLNTVS SGSGSTSGIG SGGGGGSGVV STVVQPYDVE IRRGENEGFG FVIVSSVSRP 1030 1040 1050 1060 1070 1080 EAGTTFAGNA CVAMPHKIGR IIEGSPADRC GKLKVGDRIL AVNGCSITNK SHSDIVNLIK 1090 1100 1110 1120 1130 1140 EAGNTVTLRI IPGDESSNAT LLTNAEKIAT ITTTHTPSQQ GTQETRNTTK PKQESQFEFK 1150 1160 1170 1180 1190 1200 APQATQEQDF YTVELERGAK GFGFSLRGGR EYNMDLYVLR LAEDGPAERC GKMRIGDEIL 1210 1220 1230 1240 1250 1260 EINGETTKNM KHSRAIELIK NGGRRVRLFL KRGDGSVPEY DPSSDRHGPA TGPQGVPEVR 1270 1280 1290 1300 1310 1320 AGPDRRQHPS LESSYPPDLH KSSPHGEKRA HARDPKGSRE YSRQPNEHHT WNGTSRKPDS 1330 1340 1350 1360 1370 1380 GACRPKDRAP EGRRDAQAER AAAANGPKRR SPEKRREGTR SADNTLERRE KHEKRRDVSP 1390 1400 1410 1420 1430 1440 ERRRERSPTR RRDGSPSRRR RSLERLLEQR RSPERRRGGS PERRAKSTDR RRARSPERRR 1450 1460 1470 1480 1490 ERSLDKRNRE DRASHREREE ANLKQDAGRS SRHPPEQRRR PYKECSTDLS I
	Isoform 2 (MAGI-1C-beta) [UniParc]. Checksum: 2E98A448A9E7DF89		1,462	161,610
	10 20 30 40 50 60 MSKVIQKKNH WTSRVHECTV KRGPQGELGV TVLGGAEHGE FPYVGAVAAV EAAGLPGGGE 70 80 90 100 110 120 GPRLGEGELL LEVQGVRVSG LPRYDVLGVI DSCKEAVTFK AVRQGGRLNK DLRHFLNQRF 130 140 150 160 170 180 QKGFPDHELQ QTIRDNLYRH AVPCTTRSPR EGEVPGVDYN FLTVKEFLDL EQSGTLLEVG 190 200 210 220 230 240 TYEGNYYGTP KPPSQPVSGK VITTDALHSL QSGSKQSTPK RTKSYNDMQN AGIVHAENEE 250 260 270 280 290 300 EDDVPEMNSS FTADSGEQEE HTLQETALPP VNSSIIAAPI TDPSQKFPQY LPLSAEDNLG 310 320 330 340 350 360 PLPENWEMAY TENGEVYFID HNTKTTSWLD PRCLNKQQKP LEECEDDEGV HTEELDSELE 370 380 390 400 410 420 LPAGWEKIED PVYGIYYVDH INRKTQYENP VLEAKRKKQL EQQQQQQQQQ QQQQQQQQQQ 430 440 450 460 470 480 QTEEWTEDHS ALVPPVIPNH PPSNPEPARE VPLQGKPFFT RNPSELKGKF IHTKLRKSSR 490 500 510 520 530 540 GFGFTVVGGD EPDEFLQIKS LVLDGPAALD GKMETGDVIV SVNDTCVLGH THAQVVKIFQ 550 560 570 580 590 600 SIPIGASVDL ELCRGYPLPF DPDDPNTSLV TSVAILDKEP IIVNGQETYD SPASHSSKTG 610 620 630 640 650 660 KVNGMKDARP SSPADVASNS SHGYPNDTVS LASSIATQPE LITVHIVKGP MGFGFTIADS 670 680 690 700 710 720 PGGGGQRVKQ IVDSPRCRGL KEGDLIVEVN KKNVQALTHN QVVDMLVECP KGSEVTLLVQ 730 740 750 760 770 780 RGGLPVPKKS PKSQPLERKD SQNSSQHSVS SHRSLHTASP SHSTQVLPEF PPAEAQAPDQ 790 800 810 820 830 840 TDSSGQKKPD PFKIWAQSRS MYENRLPDYQ EQDIFLWRKE TGFGFRILGG NEPGEPIYIG 850 860 870 880 890 900 HIVPLGAADT DGRLRSGDEL ICVDGTPVIG KSHQLVVQLM QQAAKQGHVN LTVRRKVVFA 910 920 930 940 950 960 VPKTENEVPS PASSHHSSNQ PASLTEEKRT PQGSQNSLNT VSSGSGSTSG IGSGGGGGSG 970 980 990 1000 1010 1020 VVSTVVQPYD VEIRRGENEG FGFVIVSSVS RPEAGTTFGN ACVAMPHKIG RIIEGSPADR 1030 1040 1050 1060 1070 1080 CGKLKVGDRI LAVNGCSITN KSHSDIVNLI KEAGNTVTLR IIPGDESSNA TLLTNAEKIA 1090 1100 1110 1120 1130 1140 TITTTHTPSQ QGTQETRNTT KPKQESQFEF KAPQATQEQD FYTVELERGA KGFGFSLRGG 1150 1160 1170 1180 1190 1200 REYNMDLYVL RLAEDGPAER CGKMRIGDEI LEINGETTKN MKHSRAIELI KNGGRRVRLF 1210 1220 1230 1240 1250 1260 LKRGDGSVPE YDPSSDRHGP ATGPQGVPEV RAGPDRRQHP SLESSYPPDL HKSSPHGEKR 1270 1280 1290 1300 1310 1320 AHARDPKGSR EYSRQPNEHH TWNGTSRKPD SGACRPKDRA PEGRRDAQAE RAAAANGPKR 1330 1340 1350 1360 1370 1380 RSPEKRREGT RSADNTLERR EKHEKRRDVS PERRRERSPT RRRDGSPSRR RRSLERLLEQ 1390 1400 1410 1420 1430 1440 RRSPERRRGG SPERRAKSTD RRRARSPERR RERSLDKRNR EDRASHRERE EANLKQDAGR 1450 1460 SSRHPPEQRR RPYKECSTDL SI
	Isoform 3 (MAGI-1A-alpha-beta1) [UniParc]. Checksum: 83FADE2091A4C8E4		1,256	136,981