ID IMPG2_MOUSE Reviewed; 1243 AA.
AC Q80XH2; Q810Y3; Q8C8E4;
DT 26-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2003, sequence version 1.
DT 24-JAN-2024, entry version 135.
DE RecName: Full=Interphotoreceptor matrix proteoglycan 2;
DE AltName: Full=Sialoprotein associated with cones and rods proteoglycan;
DE Short=Spacrcan;
DE Flags: Precursor;
GN Name=Impg2;
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]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2), TISSUE SPECIFICITY, AND
RP DEVELOPMENTAL STAGE.
RX PubMed=12589770; DOI=10.1016/s0014-4835(02)00273-7;
RA Chen Q., Lee J.W., Nishiyama K., Shadrach K.G., Rayborn M.E.,
RA Hollyfield J.G.;
RT "SPACRCAN in the interphotoreceptor matrix of the mouse retina: molecular,
RT developmental and promoter analysis.";
RL Exp. Eye Res. 76:1-14(2003).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 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 [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 965-1243 (ISOFORM 1).
RC STRAIN=C57BL/6J; TISSUE=Cerebellum;
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 [4]
RP BINDING REGIONS, AND MUTAGENESIS OF ARG-255; ARG-263; ARG-1083; ARG-1091;
RP 1136-ARG--ARG-1139 AND ARG-1147.
RX PubMed=15044457; DOI=10.1074/jbc.m401584200;
RA Chen Q., Cai S., Shadrach K.G., Prestwich G.D., Hollyfield J.G.;
RT "Spacrcan binding to hyaluronan and other glycosaminoglycans. Molecular and
RT biochemical studies.";
RL J. Biol. Chem. 279:23142-23150(2004).
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- and hyaluronan-binding proteoglycan
CC involved in the organization of interphotoreceptor matrix; may
CC participate in the maturation and maintenance of the light-sensitive
CC photoreceptor outer segment. Binds heparin.
CC {ECO:0000250|UniProtKB:Q9BZV3}.
CC -!- SUBCELLULAR LOCATION: Photoreceptor outer segment membrane
CC {ECO:0000269|PubMed:29777959}; Single-pass type I membrane protein
CC {ECO:0000255}. Photoreceptor inner segment membrane
CC {ECO:0000269|PubMed:29777959}; Single-pass type I membrane protein
CC {ECO:0000255}. Secreted, extracellular space, extracellular matrix,
CC interphotoreceptor matrix {ECO:0000269|PubMed:29777959}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=2;
CC Name=1;
CC IsoId=Q80XH2-1; Sequence=Displayed;
CC Name=2;
CC IsoId=Q80XH2-2; Sequence=VSP_031612;
CC -!- TISSUE SPECIFICITY: Expressed in the retina (at protein level)
CC (PubMed:12589770, PubMed:29777959). Expressed in the pineal gland
CC (PubMed:12589770). {ECO:0000269|PubMed:12589770,
CC ECO:0000269|PubMed:29777959}.
CC -!- DEVELOPMENTAL STAGE: Increasing expression in retina from 15 dpc to
CC adulthood: expressed at P8 when photoreceptor outer segments are in
CC active stages of elongation; elevated expression at P10 in the
CC developing IPM and at P15 in the region adjacent to the retina pigment
CC epithelium (RPE). From P18 to P35, more homogeneously present in the
CC IPM surrounding both cones and rods. {ECO:0000269|PubMed:12589770}.
CC -!- SEQUENCE CAUTION:
CC Sequence=AAO21221.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};
CC Sequence=AAO21221.1; Type=Frameshift; Evidence={ECO:0000305};
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DR EMBL; AY174061; AAO21221.1; ALT_SEQ; mRNA.
DR EMBL; BC048863; AAH48863.1; -; mRNA.
DR EMBL; AK047356; BAC33032.1; -; mRNA.
DR CCDS; CCDS37358.1; -. [Q80XH2-1]
DR RefSeq; NP_777365.2; NM_174876.3. [Q80XH2-1]
DR AlphaFoldDB; Q80XH2; -.
DR SMR; Q80XH2; -.
DR STRING; 10090.ENSMUSP00000063648; -.
DR GlyCosmos; Q80XH2; 15 sites, No reported glycans.
DR GlyGen; Q80XH2; 15 sites.
DR iPTMnet; Q80XH2; -.
DR PhosphoSitePlus; Q80XH2; -.
DR PaxDb; 10090-ENSMUSP00000063648; -.
DR ProteomicsDB; 266977; -. [Q80XH2-1]
DR ProteomicsDB; 266978; -. [Q80XH2-2]
DR Antibodypedia; 32271; 63 antibodies from 20 providers.
DR DNASU; 224224; -.
DR Ensembl; ENSMUST00000069936.8; ENSMUSP00000063648.8; ENSMUSG00000035270.16. [Q80XH2-1]
DR Ensembl; ENSMUST00000160116.8; ENSMUSP00000125135.2; ENSMUSG00000035270.16. [Q80XH2-2]
DR GeneID; 224224; -.
DR KEGG; mmu:224224; -.
DR UCSC; uc007zmm.1; mouse. [Q80XH2-1]
DR UCSC; uc012agq.1; mouse. [Q80XH2-2]
DR AGR; MGI:3044955; -.
DR CTD; 50939; -.
DR MGI; MGI:3044955; Impg2.
DR VEuPathDB; HostDB:ENSMUSG00000035270; -.
DR eggNOG; ENOG502QT6W; Eukaryota.
DR GeneTree; ENSGT00530000063503; -.
DR HOGENOM; CLU_005111_0_0_1; -.
DR InParanoid; Q80XH2; -.
DR OMA; ESSIWPW; -.
DR OrthoDB; 4244504at2759; -.
DR PhylomeDB; Q80XH2; -.
DR TreeFam; TF331340; -.
DR BioGRID-ORCS; 224224; 3 hits in 79 CRISPR screens.
DR PRO; PR:Q80XH2; -.
DR Proteomes; UP000000589; Chromosome 16.
DR RNAct; Q80XH2; Protein.
DR Bgee; ENSMUSG00000035270; Expressed in layer of retina and 38 other cell types or tissues.
DR GO; GO:0042995; C:cell projection; IEA:UniProtKB-KW.
DR GO; GO:0031012; C:extracellular matrix; TAS:MGI.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-KW.
DR GO; GO:0033165; C:interphotoreceptor matrix; IDA:MGI.
DR GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR GO; GO:0043235; C:receptor complex; ISO:MGI.
DR GO; GO:0008201; F:heparin binding; IDA:MGI.
DR GO; GO:0005540; F:hyaluronic acid binding; IDA:MGI.
DR GO; GO:0030198; P:extracellular matrix organization; IMP:MGI.
DR GO; GO:0008104; P:protein localization; IMP:MGI.
DR GO; GO:0060042; P:retina morphogenesis in camera-type eye; IMP:MGI.
DR GO; GO:0007601; P:visual perception; IEA:InterPro.
DR Gene3D; 3.30.70.960; SEA domain; 1.
DR InterPro; IPR000742; EGF-like_dom.
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:SF4; INTERPHOTORECEPTOR MATRIX PROTEOGLYCAN 2; 1.
DR Pfam; PF01390; SEA; 2.
DR SMART; SM00200; SEA; 2.
DR SUPFAM; SSF82671; SEA domain; 2.
DR PROSITE; PS01186; EGF_2; 1.
DR PROSITE; PS50026; EGF_3; 2.
DR PROSITE; PS50024; SEA; 2.
PE 1: Evidence at protein level;
KW Alternative splicing; Cell projection; Disulfide bond; EGF-like domain;
KW Extracellular matrix; Glycoprotein; Heparin-binding; Membrane; Receptor;
KW Reference proteome; Repeat; Secreted; Signal; Transmembrane;
KW Transmembrane helix.
FT SIGNAL 1..27
FT /evidence="ECO:0000255"
FT CHAIN 28..1243
FT /note="Interphotoreceptor matrix proteoglycan 2"
FT /id="PRO_0000320150"
FT TOPO_DOM 28..1106
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 1107..1127
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 1128..1243
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT DOMAIN 235..349
FT /note="SEA 1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00188"
FT DOMAIN 900..1013
FT /note="SEA 2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00188"
FT DOMAIN 1013..1054
FT /note="EGF-like 1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT DOMAIN 1055..1096
FT /note="EGF-like 2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT REGION 205..234
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 255..263
FT /note="Hyaluronan-binding motif involved in chondroitin
FT sulfate A-binding"
FT REGION 748..768
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 1083..1091
FT /note="Hyaluronan-binding motif involved in chondroitin
FT sulfate C-binding"
FT REGION 1128..1136
FT /note="Hyaluronan-binding motif involved in chondroitin
FT sulfate A- and C-binding"
FT REGION 1139..1147
FT /note="Hyaluronan-binding motif involved in chondroitin
FT sulfate C-binding"
FT REGION 1212..1220
FT /note="Hyaluronan-binding motif involved in chondroitin
FT sulfate A- and C-binding motif"
FT COMPBIAS 205..232
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 748..766
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT CARBOHYD 225
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 297
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 316
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 366
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 427
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 428
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 429
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 582
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 701
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 704
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 712
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 817
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 888
FT /note="O-linked (GalNAc...) threonine"
FT /evidence="ECO:0000255"
FT CARBOHYD 945
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 959
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT DISULFID 1017..1028
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT DISULFID 1022..1039
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT DISULFID 1041..1053
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT DISULFID 1057..1070
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT DISULFID 1064..1080
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT DISULFID 1082..1095
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00076"
FT VAR_SEQ 381..489
FT /note="Missing (in isoform 2)"
FT /evidence="ECO:0000303|PubMed:12589770"
FT /id="VSP_031612"
FT MUTAGEN 255
FT /note="R->H: Decreased-binding affinity to hyaluronan."
FT /evidence="ECO:0000269|PubMed:15044457"
FT MUTAGEN 263
FT /note="R->H: Decreased-binding affinity to hyaluronan."
FT /evidence="ECO:0000269|PubMed:15044457"
FT MUTAGEN 1083
FT /note="R->Q: Decreased-binding affinity to hyaluronan."
FT /evidence="ECO:0000269|PubMed:15044457"
FT MUTAGEN 1091
FT /note="R->Q: Decreased-binding affinity to hyaluronan."
FT /evidence="ECO:0000269|PubMed:15044457"
FT MUTAGEN 1136..1139
FT /note="RRER->SSES: Most important decrease in binding
FT affinity to hyaluronan."
FT /evidence="ECO:0000269|PubMed:15044457"
FT MUTAGEN 1147
FT /note="R->G: Important decrease in binding affinity to
FT hyaluronan."
FT /evidence="ECO:0000269|PubMed:15044457"
SQ SEQUENCE 1243 AA; 138102 MW; 26C647136491E4D5 CRC64;
MIMFLPVGRM SLGILILFLT GGNLVSASEE RQEPMHAVSV LSPEKSTDLS LPTRKRQLLD
ATETGRRWLL RRRRSILFPN GVKICSSETV AEAVANHVKY FKARVCQEAI WEAFRTFWDR
LPGRDEYRHW MNLCEDGVTS VFEMGAHFSQ SVEHRNLIMK KLAYTREAES SSCKDQSCGP
ELSFPVPIGE TSTLTGAVSS ASYPGLASES SAASPQESIS NEIENVTEEP TQPAAEQIAE
FSIQLLGKRY SEELRDPSSA LYRLLVEEFI SEVEKAFTGL PGYKGIRVLE FRAPEENDSG
IDVHYAVTFN GEAISNTTWD LISLHSNKVE NHGLVEMDDK PTAVYTISNF RDYIAETLHQ
NFLMGNSSLN PDPKSLQLIN VRGVLLPQTE DIVWNTQSSS LQVTTSSILD NTLQAEWLSA
DTTTTTTTTI SPFGFSSSSP SATGRELQSQ SALRDVVSTS KLASPTKVVL SSLPEILGGS
SLTLHSVTPA VLQPDLPVAP EGRTSGSFIL EDGLASTEEL EDTSIDGLPS SPLIQPVPKE
TVPPMEDSDT ALLSTPHLTS SAIEDLTKDI GTPSGLESLA SNISDQLEVI PWFPDTSVEK
DFIFESGLGS GSGKDVDVID WPWSETSLEK TTKPLSKSWS EEQDALLPTE GREKLHIDGR
VDSTEQIIES SEHRYGDRPI HFIEEESHVR STIPIFVESA TPPTSPIFSK HTSDVPDIDS
YSLTKPPFLP VTIAIPASTK KTDEVLKEDM VHTESSSHKE LDSEVPVSRP DMQPVWTMLP
ESDTVWTRTS SLGKLSRDTL ASTPESTDRL WLKASMTQST ELPSTTHSTQ LEEEVIMAVQ
DISLELDQVG TDYYQSELTE EQHGKADSYV EMSTSVHYTE MPIVALPTKG GVLSHTQTAG
ALVVFFSLRV TNMLFSEDLF NKNSLEYKAL EQRFLELLVP YLQSNLSGFQ NLEILSFRNG
SIVVNSRVRF AESAPPNVNK AMYRILEDFC TTAYQTMNLD IDKYSLDVES GDEANPCKFQ
ACNEFSECLV NPWSGEAKCK CYPGYLSVDE LPCQSLCDLQ PDFCLNDGKC DIMPGHGAIC
RCRVGSNWWY RGQHCEEFVS EPFVIGITIA SVVSFLLVAS AVVFFLVKML QAQNVRRERQ
RPTSSSRHPD SLSSVENAMK YNPAYESHLA GCELYEKSYS QHPFYSSASE EVIGGLSREE
IRQMYESSDL SKEEIQERMR ILELYANDPE FAAFVREHQM EEL
//
