ID   IMPG1_MOUSE             Reviewed;         798 AA.
AC   Q8R1W8; Q9CTP8; Q9ES62; Q9ET31;
DT   03-OCT-2006, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2002, sequence version 1.
DT   24-JAN-2024, entry version 124.
DE   RecName: Full=Interphotoreceptor matrix proteoglycan 1;
DE   AltName: Full=Interphotoreceptor matrix proteoglycan of 150 kDa;
DE            Short=IPM-150;
DE   AltName: Full=Sialoprotein associated with cones and rods;
DE   Flags: Precursor;
GN   Name=Impg1 {ECO:0000312|MGI:MGI:1926876};
GN   Synonyms=Spacr {ECO:0000303|PubMed:10995555};
OS   Mus musculus (Mouse).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae;
OC   Murinae; Mus; Mus.
OX   NCBI_TaxID=10090;
RN   [1] {ECO:0000305, ECO:0000312|EMBL:AAG32162.1}
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2), SUBCELLULAR LOCATION, TISSUE
RP   SPECIFICITY, AND IDENTIFICATION BY MASS SPECTROMETRY.
RX   PubMed=10995555; DOI=10.1006/exer.2000.0888;
RA   Lee J.W., Chen Q., Rayborn M.E., Shadrach K.G., Crabb J.W., Rodriguez I.R.,
RA   Hollyfield J.G.;
RT   "SPACR in the interphotoreceptor matrix of the mouse retina: molecular,
RT   biochemical and immunohistochemical characterization.";
RL   Exp. Eye Res. 71:341-352(2000).
RN   [2] {ECO:0000305, ECO:0000312|EMBL:AAG00796.1}
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), AND TISSUE SPECIFICITY.
RX   PubMed=10958699;
RA   Kuehn M.H., Wietecki D.T., Hageman G.S.;
RT   "Molecular characterization of the murine orthologue of the human retinal
RT   proteoglycan IPM 150.";
RL   Mol. Vis. 6:148-156(2000).
RN   [3] {ECO:0000305, ECO:0000312|EMBL:AAH22970.1}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
RC   TISSUE=Eye {ECO:0000312|EMBL:AAH22970.1};
RX   PubMed=15489334; DOI=10.1101/gr.2596504;
RG   The MGC Project Team;
RT   "The status, quality, and expansion of the NIH full-length cDNA project:
RT   the Mammalian Gene Collection (MGC).";
RL   Genome Res. 14:2121-2127(2004).
RN   [4] {ECO:0000305, ECO:0000312|EMBL:BAB32231.3}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 1-293 (ISOFORM 3).
RC   STRAIN=C57BL/6J {ECO:0000312|EMBL:BAB32231.3};
RC   TISSUE=Retina {ECO:0000312|EMBL:BAB32231.3};
RX   PubMed=16141072; DOI=10.1126/science.1112014;
RA   Carninci P., Kasukawa T., Katayama S., Gough J., Frith M.C., Maeda N.,
RA   Oyama R., Ravasi T., Lenhard B., Wells C., Kodzius R., Shimokawa K.,
RA   Bajic V.B., Brenner S.E., Batalov S., Forrest A.R., Zavolan M., Davis M.J.,
RA   Wilming L.G., Aidinis V., Allen J.E., Ambesi-Impiombato A., Apweiler R.,
RA   Aturaliya R.N., Bailey T.L., Bansal M., Baxter L., Beisel K.W., Bersano T.,
RA   Bono H., Chalk A.M., Chiu K.P., Choudhary V., Christoffels A.,
RA   Clutterbuck D.R., Crowe M.L., Dalla E., Dalrymple B.P., de Bono B.,
RA   Della Gatta G., di Bernardo D., Down T., Engstrom P., Fagiolini M.,
RA   Faulkner G., Fletcher C.F., Fukushima T., Furuno M., Futaki S.,
RA   Gariboldi M., Georgii-Hemming P., Gingeras T.R., Gojobori T., Green R.E.,
RA   Gustincich S., Harbers M., Hayashi Y., Hensch T.K., Hirokawa N., Hill D.,
RA   Huminiecki L., Iacono M., Ikeo K., Iwama A., Ishikawa T., Jakt M.,
RA   Kanapin A., Katoh M., Kawasawa Y., Kelso J., Kitamura H., Kitano H.,
RA   Kollias G., Krishnan S.P., Kruger A., Kummerfeld S.K., Kurochkin I.V.,
RA   Lareau L.F., Lazarevic D., Lipovich L., Liu J., Liuni S., McWilliam S.,
RA   Madan Babu M., Madera M., Marchionni L., Matsuda H., Matsuzawa S., Miki H.,
RA   Mignone F., Miyake S., Morris K., Mottagui-Tabar S., Mulder N., Nakano N.,
RA   Nakauchi H., Ng P., Nilsson R., Nishiguchi S., Nishikawa S., Nori F.,
RA   Ohara O., Okazaki Y., Orlando V., Pang K.C., Pavan W.J., Pavesi G.,
RA   Pesole G., Petrovsky N., Piazza S., Reed J., Reid J.F., Ring B.Z.,
RA   Ringwald M., Rost B., Ruan Y., Salzberg S.L., Sandelin A., Schneider C.,
RA   Schoenbach C., Sekiguchi K., Semple C.A., Seno S., Sessa L., Sheng Y.,
RA   Shibata Y., Shimada H., Shimada K., Silva D., Sinclair B., Sperling S.,
RA   Stupka E., Sugiura K., Sultana R., Takenaka Y., Taki K., Tammoja K.,
RA   Tan S.L., Tang S., Taylor M.S., Tegner J., Teichmann S.A., Ueda H.R.,
RA   van Nimwegen E., Verardo R., Wei C.L., Yagi K., Yamanishi H.,
RA   Zabarovsky E., Zhu S., Zimmer A., Hide W., Bult C., Grimmond S.M.,
RA   Teasdale R.D., Liu E.T., Brusic V., Quackenbush J., Wahlestedt C.,
RA   Mattick J.S., Hume D.A., Kai C., Sasaki D., Tomaru Y., Fukuda S.,
RA   Kanamori-Katayama M., Suzuki M., Aoki J., Arakawa T., Iida J., Imamura K.,
RA   Itoh M., Kato T., Kawaji H., Kawagashira N., Kawashima T., Kojima M.,
RA   Kondo S., Konno H., Nakano K., Ninomiya N., Nishio T., Okada M., Plessy C.,
RA   Shibata K., Shiraki T., Suzuki S., Tagami M., Waki K., Watahiki A.,
RA   Okamura-Oho Y., Suzuki H., Kawai J., Hayashizaki Y.;
RT   "The transcriptional landscape of the mammalian genome.";
RL   Science 309:1559-1563(2005).
RN   [5]
RP   SUBCELLULAR LOCATION, AND TISSUE SPECIFICITY.
RX   PubMed=29777959; DOI=10.1016/j.actbio.2018.05.023;
RA   Felemban M., Dorgau B., Hunt N.C., Hallam D., Zerti D., Bauer R., Ding Y.,
RA   Collin J., Steel D., Krasnogor N., Al-Aama J., Lindsay S., Mellough C.,
RA   Lako M.;
RT   "Extracellular matrix component expression in human pluripotent stem cell-
RT   derived retinal organoids recapitulates retinogenesis in vivo and reveals
RT   an important role for IMPG1 and CD44 in the development of photoreceptors
RT   and interphotoreceptor matrix.";
RL   Acta Biomater. 74:207-221(2018).
CC   -!- FUNCTION: Chondroitin sulfate-, heparin- and hyaluronan-binding protein
CC       (By similarity). May serve to form a basic macromolecular scaffold
CC       comprising the insoluble interphotoreceptor matrix (By similarity).
CC       {ECO:0000250|UniProtKB:Q17R60, ECO:0000250|UniProtKB:Q8JIR8}.
CC   -!- SUBCELLULAR LOCATION: Cell projection, cilium, photoreceptor outer
CC       segment {ECO:0000250|UniProtKB:Q17R60}. Secreted, extracellular space,
CC       extracellular matrix, interphotoreceptor matrix
CC       {ECO:0000269|PubMed:10995555, ECO:0000269|PubMed:29777959}.
CC       Photoreceptor inner segment {ECO:0000269|PubMed:10995555}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=3;
CC       Name=1 {ECO:0000269|PubMed:10958699, ECO:0000269|PubMed:15489334};
CC         IsoId=Q8R1W8-1; Sequence=Displayed;
CC       Name=2 {ECO:0000269|PubMed:10995555};
CC         IsoId=Q8R1W8-2; Sequence=VSP_052171;
CC       Name=3 {ECO:0000269|PubMed:16141072};
CC         IsoId=Q8R1W8-3; Sequence=VSP_052172;
CC   -!- TISSUE SPECIFICITY: Abundantly expressed in the retina (at protein
CC       level). {ECO:0000269|PubMed:10958699, ECO:0000269|PubMed:10995555,
CC       ECO:0000269|PubMed:29777959}.
CC   -!- PTM: Highly glycosylated (N- and O-linked carbohydrates and sialic
CC       acid). {ECO:0000250|UniProtKB:Q17R60}.
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DR   EMBL; AF229929; AAG32162.1; -; mRNA.
DR   EMBL; AF266478; AAG00796.1; -; mRNA.
DR   EMBL; BC022970; AAH22970.1; -; mRNA.
DR   EMBL; AK020862; BAB32231.3; -; mRNA.
DR   CCDS; CCDS57685.1; -. [Q8R1W8-1]
DR   RefSeq; NP_071299.3; NM_022016.3. [Q8R1W8-1]
DR   RefSeq; XP_006511391.1; XM_006511328.3. [Q8R1W8-1]
DR   AlphaFoldDB; Q8R1W8; -.
DR   BioGRID; 210997; 3.
DR   STRING; 10090.ENSMUSP00000108876; -.
DR   GlyCosmos; Q8R1W8; 12 sites, No reported glycans.
DR   GlyGen; Q8R1W8; 12 sites.
DR   iPTMnet; Q8R1W8; -.
DR   PhosphoSitePlus; Q8R1W8; -.
DR   PaxDb; 10090-ENSMUSP00000108876; -.
DR   ProteomicsDB; 267334; -. [Q8R1W8-1]
DR   ProteomicsDB; 267335; -. [Q8R1W8-2]
DR   ProteomicsDB; 267336; -. [Q8R1W8-3]
DR   Antibodypedia; 55141; 58 antibodies from 12 providers.
DR   DNASU; 63859; -.
DR   Ensembl; ENSMUST00000085289.12; ENSMUSP00000082395.6; ENSMUSG00000032343.16. [Q8R1W8-3]
DR   Ensembl; ENSMUST00000113250.10; ENSMUSP00000108876.3; ENSMUSG00000032343.16. [Q8R1W8-1]
DR   GeneID; 63859; -.
DR   KEGG; mmu:63859; -.
DR   UCSC; uc009qvi.2; mouse. [Q8R1W8-1]
DR   AGR; MGI:1926876; -.
DR   CTD; 3617; -.
DR   MGI; MGI:1926876; Impg1.
DR   VEuPathDB; HostDB:ENSMUSG00000032343; -.
DR   eggNOG; ENOG502QTXX; Eukaryota.
DR   GeneTree; ENSGT00530000063503; -.
DR   HOGENOM; CLU_005111_1_0_1; -.
DR   InParanoid; Q8R1W8; -.
DR   OMA; SECVMNE; -.
DR   OrthoDB; 4244504at2759; -.
DR   PhylomeDB; Q8R1W8; -.
DR   TreeFam; TF331340; -.
DR   BioGRID-ORCS; 63859; 3 hits in 78 CRISPR screens.
DR   ChiTaRS; Impg1; mouse.
DR   PRO; PR:Q8R1W8; -.
DR   Proteomes; UP000000589; Chromosome 9.
DR   RNAct; Q8R1W8; Protein.
DR   Bgee; ENSMUSG00000032343; Expressed in retinal neural layer and 8 other cell types or tissues.
DR   ExpressionAtlas; Q8R1W8; baseline and differential.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-KW.
DR   GO; GO:0033165; C:interphotoreceptor matrix; IDA:MGI.
DR   GO; GO:0001917; C:photoreceptor inner segment; IEA:UniProtKB-SubCell.
DR   GO; GO:0001750; C:photoreceptor outer segment; IEA:UniProtKB-SubCell.
DR   GO; GO:0035374; F:chondroitin sulfate binding; ISS:UniProtKB.
DR   GO; GO:0008201; F:heparin binding; ISS:UniProtKB.
DR   GO; GO:0005540; F:hyaluronic acid binding; ISS:UniProtKB.
DR   GO; GO:0030198; P:extracellular matrix organization; IMP:MGI.
DR   GO; GO:0007601; P:visual perception; IEA:InterPro.
DR   Gene3D; 3.30.70.960; SEA domain; 1.
DR   InterPro; IPR039861; IMPG.
DR   InterPro; IPR000082; SEA_dom.
DR   InterPro; IPR036364; SEA_dom_sf.
DR   PANTHER; PTHR12199; INTERPHOTORECEPTOR MATRIX PROTEOGLYCAN; 1.
DR   PANTHER; PTHR12199:SF3; INTERPHOTORECEPTOR MATRIX PROTEOGLYCAN 1; 1.
DR   Pfam; PF01390; SEA; 2.
DR   SMART; SM00200; SEA; 2.
DR   SUPFAM; SSF82671; SEA domain; 2.
DR   PROSITE; PS50024; SEA; 2.
DR   Genevisible; Q8R1W8; MM.
PE   1: Evidence at protein level;
KW   Alternative splicing; Cell projection; Extracellular matrix; Glycoprotein;
KW   Heparin-binding; Hyaluronic acid; Receptor; Reference proteome; Repeat;
KW   Secreted; Sialic acid; Signal.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000255"
FT   CHAIN           21..798
FT                   /note="Interphotoreceptor matrix proteoglycan 1"
FT                   /evidence="ECO:0000255"
FT                   /id="PRO_0000252239"
FT   DOMAIN          235..357
FT                   /note="SEA 1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00188"
FT   DOMAIN          575..688
FT                   /note="SEA 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00188"
FT   REGION          424..446
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          745..773
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOTIF           625..633
FT                   /note="Heparin- and hyaluronan-binding"
FT                   /evidence="ECO:0000250|UniProtKB:Q8JIR8"
FT   COMPBIAS        431..446
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        751..766
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   CARBOHYD        142
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        174
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        186
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        457
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        473
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        474
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        477
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        559
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        596
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        620
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        634
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        652
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   VAR_SEQ         1..56
FT                   /note="Missing (in isoform 2)"
FT                   /evidence="ECO:0000303|PubMed:10995555"
FT                   /id="VSP_052171"
FT   VAR_SEQ         23..99
FT                   /note="Missing (in isoform 3)"
FT                   /evidence="ECO:0000303|PubMed:16141072"
FT                   /id="VSP_052172"
FT   CONFLICT        3
FT                   /note="L -> F (in Ref. 2; AAG00796)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        12
FT                   /note="L -> F (in Ref. 2; AAG00796)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        224
FT                   /note="K -> I (in Ref. 1; AAG32162)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   798 AA;  89474 MW;  E875FB5587389D4C CRC64;
     MNLQIKHAIF VLGIFLQVQG IKDTSIKIFS SEIKNIDKTP RIETIESTST VHKVSTMKRI
     FDLPKLRTKR SALFPAANIC PQESLRQILA SLQEYYRLRV CQEVVWEAYR IFLDRIPDTE
     EYQDWVSLCQ KETFCLFDIG KNFSNSQEHL DLLQQRIKQR SFPGRKDETA SMETLEAPTE
     APVVPTDVSR MSLGPFPLPS DDTDLKEILS VTLKDIQKPT TESKTEPIHV SEFSSEEKVE
     FSISLPNHRF KAELTNSGSP YYQELVGQSQ LQLQKIFKKL PGFGEIRVLG FRPKKEEDGS
     SSTEIQLMAI FKRDHAEAKS PDSHLLSLDS NKIESERIHH GVIEDKQPET YLTATDLKKL
     IIQLLDGDLS LVEGKIPFGD EVTGTLFRPV TEPDLPKPLA DVTEDATLSP ELPFVEPRLE
     AVDREGSELP GMSSKDSSWS PPVSASISRS ENLPSFTPSI FSLDAQSPPP LMTTGPTALI
     PKPTLPTIDY STIRQLPLES SHWPASSSDR ELITSSHDTI RDLDGMDVSD TPALSEISEL
     SGYDSASGQF LEMTTPIPTV RFITTSSETI ATKGQELVVF FSLRVANMPF SYDLFNKSSL
     EYQALEQRFT DLLVPYLRSN LTGFKQLEIL SFRNGSVIVN SKVRFAKAVP YNLTQAVRGV
     LEDLRSTAAQ GLNLEIESYS LDIEPADQAD PCKLLDCGKF AQCVKNEWTE EAECRCRQGH
     ESHGTLDYQT LNLCPPGKTC VAGREQATPC RPPDHSTNQA QEPGVKKLRQ QNKVVKKRNS
     KLSAIGFEEF EDQDWEGN
//