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Protein

Liprin-alpha-3

Gene

PPFIA3

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

May regulate the disassembly of focal adhesions. May localize receptor-like tyrosine phosphatases type 2A at specific sites on the plasma membrane, possibly regulating their interaction with the extracellular environment and their association with substrates.1 Publication

GO - Biological processi

Complete GO annotation...

Enzyme and pathway databases

ReactomeiREACT_12591. Glutamate Neurotransmitter Release Cycle.
REACT_15293. Dopamine Neurotransmitter Release Cycle.
REACT_15309. Acetylcholine Neurotransmitter Release Cycle.
REACT_15418. Norepinephrine Neurotransmitter Release Cycle.
REACT_15425. Serotonin Neurotransmitter Release Cycle.

Names & Taxonomyi

Protein namesi
Recommended name:
Liprin-alpha-3
Alternative name(s):
Protein tyrosine phosphatase receptor type f polypeptide-interacting protein alpha-3
Short name:
PTPRF-interacting protein alpha-3
Gene namesi
Name:PPFIA3
Synonyms:KIAA0654
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640 Componenti: Chromosome 19

Organism-specific databases

HGNCiHGNC:9247. PPFIA3.

Subcellular locationi

  • Cytoplasm By similarity
  • Cell surface By similarity

  • Note: Colocalizes with PTPRF at the cell surface.By similarity

GO - Cellular componenti

  • cell surface Source: UniProtKB-SubCell
  • cytosol Source: Reactome
  • presynaptic active zone Source: ParkinsonsUK-UCL
Complete GO annotation...

Keywords - Cellular componenti

Cytoplasm

Pathology & Biotechi

Organism-specific databases

PharmGKBiPA33568.

Polymorphism and mutation databases

BioMutaiPPFIA3.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 11941194Liprin-alpha-3PRO_0000191029Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei17 – 171Phosphoserine1 Publication
Modified residuei207 – 2071Phosphoserine1 Publication
Modified residuei645 – 6451PhosphoserineBy similarity
Modified residuei714 – 7141Phosphothreonine1 Publication
Modified residuei718 – 7181Phosphothreonine1 Publication

Keywords - PTMi

Phosphoprotein

Proteomic databases

MaxQBiO75145.
PaxDbiO75145.
PRIDEiO75145.

PTM databases

PhosphoSiteiO75145.

Expressioni

Tissue specificityi

Expressed only in brain.1 Publication

Gene expression databases

BgeeiO75145.
CleanExiHS_PPFIA3.
ExpressionAtlasiO75145. baseline and differential.
GenevisibleiO75145. HS.

Organism-specific databases

HPAiHPA043567.
HPA050340.

Interactioni

Subunit structurei

Forms homodimers and heterodimers with liprins-alpha and liprins-beta. Interacts with the second PTPase domain of PTPRD, PTPRF and PTPRS. Binds RIMS1, RIMS2, RIMS3 and RIMS4 (By similarity).By similarity

Protein-protein interaction databases

BioGridi114111. 9 interactions.
IntActiO75145. 2 interactions.
MINTiMINT-3001008.
STRINGi9606.ENSP00000335614.

Structurei

3D structure databases

ProteinModelPortaliO75145.
SMRiO75145. Positions 812-1115.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini838 – 90467SAM 1PROSITE-ProRule annotationAdd
BLAST
Domaini953 – 101765SAM 2PROSITE-ProRule annotationAdd
BLAST
Domaini1041 – 111070SAM 3PROSITE-ProRule annotationAdd
BLAST

Coiled coil

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Coiled coili26 – 133108Sequence AnalysisAdd
BLAST
Coiled coili161 – 501341Sequence AnalysisAdd
BLAST
Coiled coili596 – 64449Sequence AnalysisAdd
BLAST
Coiled coili1014 – 104027Sequence AnalysisAdd
BLAST

Domaini

The N-terminal coiled coil regions mediate homodimerization preferentially and heterodimerization type alpha/alpha. The C-terminal, non-coiled coil regions mediate heterodimerization type alpha/beta and interaction with PTPRD, PTPRF and PTPRS.

Sequence similaritiesi

Belongs to the liprin family. Liprin-alpha subfamily.Curated
Contains 3 SAM (sterile alpha motif) domains.PROSITE-ProRule annotation

Keywords - Domaini

Coiled coil, Repeat

Phylogenomic databases

eggNOGiNOG322697.
GeneTreeiENSGT00760000119138.
HOGENOMiHOG000017513.
HOVERGENiHBG052330.
InParanoidiO75145.
OMAiSKRQEWE.
OrthoDBiEOG7T7GS7.
PhylomeDBiO75145.
TreeFamiTF314207.

Family and domain databases

Gene3Di1.10.150.50. 2 hits.
InterProiIPR029515. Liprin.
IPR030440. PPFIA3.
IPR001660. SAM.
IPR013761. SAM/pointed.
IPR011510. SAM_2.
IPR021129. SAM_type1.
[Graphical view]
PANTHERiPTHR12587. PTHR12587. 1 hit.
PTHR12587:SF4. PTHR12587:SF4. 1 hit.
PfamiPF00536. SAM_1. 2 hits.
PF07647. SAM_2. 1 hit.
[Graphical view]
SMARTiSM00454. SAM. 3 hits.
[Graphical view]
SUPFAMiSSF47769. SSF47769. 3 hits.
PROSITEiPS50105. SAM_DOMAIN. 3 hits.
[Graphical view]

Sequences (2)i

Sequence statusi: Complete.

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: O75145-1) [UniParc]FASTAAdd to basket

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.

« Hide

        10         20         30         40         50
MMCEVMPTIS EDGRRGSALG PDEAGGELER LMVTMLTERE RLLETLREAQ
60 70 80 90 100
DGLATAQLRL RELGHEKDSL QRQLSIALPQ EFAALTKELN LCREQLLERE
110 120 130 140 150
EEIAELKAER NNTRLLLEHL ECLVSRHERS LRMTVVKRQA QSPGGVSSEV
160 170 180 190 200
EVLKALKSLF EHHKALDEKV RERLRMALER VAVLEEELEL SNQETLNLRE
210 220 230 240 250
QLSRRRSGLE EPGKDGDGQT LANGLGPGGD SNRRTAELEE ALERQRAEVC
260 270 280 290 300
QLRERLAVLC RQMSQLEEEL GTAHRELGKA EEANSKLQRD LKEALAQRED
310 320 330 340 350
MEERITTLEK RYLSAQREAT SLHDANDKLE NELASKESLY RQSEEKSRQL
360 370 380 390 400
AEWLDDAKQK LQQTLQKAET LPEIEAQLAQ RVAALNKAEE RHGNFEERLR
410 420 430 440 450
QLEAQLEEKN QELQRARQRE KMNDDHNKRL SETVDKLLSE SNERLQLHLK
460 470 480 490 500
ERMGALEEKN SLSEEIANMK KLQDELLLNK EQLLAEMERM QMEIDQLRGR
510 520 530 540 550
PPSSYSRSLP GSALELRYSQ APTLPSGAHL DPYVAGSGRA GKRGRWSGVK
560 570 580 590 600
EEPSKDWERS APAGSIPPPF PGELDGSDEE EAEGMFGAEL LSPSGQADVQ
610 620 630 640 650
TLAIMLQEQL EAINKEIKLI QEEKETTEQR AEELESRVSS SGLDSLGRYR
660 670 680 690 700
SSCSLPPSLT TSTLASPSPP SSGHSTPRLA PPSPAREGTD KANHVPKEEA
710 720 730 740 750
GAPRGEGPAI PGDTPPPTPR SARLERMTQA LALQAGSLED GGPPRGSEGT
760 770 780 790 800
PDSLHKAPKK KSIKSSIGRL FGKKEKGRMG PPGRDSSSLA GTPSDETLAT
810 820 830 840 850
DPLGLAKLTG PGDKDRRNKR KHELLEEACR QGLPFAAWDG PTVVSWLELW
860 870 880 890 900
VGMPAWYVAA CRANVKSGAI MANLSDTEIQ REIGISNPLH RLKLRLAIQE
910 920 930 940 950
MVSLTSPSAP ASSRTSTGNV WMTHEEMESL TATTKPETKE ISWEQILAYG
960 970 980 990 1000
DMNHEWVGND WLPSLGLPQY RSYFMESLVD ARMLDHLNKK ELRGQLKMVD
1010 1020 1030 1040 1050
SFHRVSLHYG IMCLKRLNYD RKDLERRREE SQTQIRDVMV WSNERVMGWV
1060 1070 1080 1090 1100
SGLGLKEFAT NLTESGVHGA LLALDETFDY SDLALLLQIP TQNAQARQLL
1110 1120 1130 1140 1150
EKEFSNLISL GTDRRLDEDS AKSFSRSPSW RKMFREKDLR GVTPDSAEML
1160 1170 1180 1190
PPNFRSAAAG ALGSPGLPLR KLQPEGQTSG SSRADGVSVR TYSC
Length:1,194
Mass (Da):133,496
Last modified:February 16, 2004 - v3
Checksum:i4DD92531AD8AE12D
GO
Isoform 2 (identifier: O75145-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     937-945: Missing.

Note: May be due to exon skipping.
Show »
Length:1,185
Mass (Da):132,365
Checksum:i2D4AAB5416E93397
GO

Sequence cautioni

The sequence BAA31629.2 differs from that shown. Reason: Erroneous initiation. Curated

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti878 – 8781E → K in AAC26101 (PubMed:9624153).Curated
Sequence conflicti1011 – 10111I → V in AAC26101 (PubMed:9624153).Curated

Natural variant

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti563 – 5631A → S.3 Publications
Corresponds to variant rs2303053 [ dbSNP | Ensembl ].
VAR_017757

Alternative sequence

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Alternative sequencei937 – 9459Missing in isoform 2. 2 PublicationsVSP_009392

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AB014554 mRNA. Translation: BAA31629.2. Different initiation.
AK023850 mRNA. Translation: BAB14702.1.
AK025972 mRNA. No translation available.
AK289757 mRNA. Translation: BAF82446.1.
CH471177 Genomic DNA. Translation: EAW52457.1.
BC021255 mRNA. Translation: AAH21255.2.
BC101518 mRNA. Translation: AAI01519.1.
BC101520 mRNA. Translation: AAI01521.1.
AF034800 mRNA. Translation: AAC26101.1.
CCDSiCCDS12758.1. [O75145-1]
RefSeqiNP_003651.1. NM_003660.3. [O75145-1]
XP_006723513.1. XM_006723450.1. [O75145-2]
UniGeneiHs.413748.
Hs.604638.

Genome annotation databases

EnsembliENST00000334186; ENSP00000335614; ENSG00000177380.
ENST00000602351; ENSP00000473622; ENSG00000177380. [O75145-2]
GeneIDi8541.
KEGGihsa:8541.
UCSCiuc002pmr.3. human. [O75145-1]
uc002pms.3. human. [O75145-2]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AB014554 mRNA. Translation: BAA31629.2. Different initiation.
AK023850 mRNA. Translation: BAB14702.1.
AK025972 mRNA. No translation available.
AK289757 mRNA. Translation: BAF82446.1.
CH471177 Genomic DNA. Translation: EAW52457.1.
BC021255 mRNA. Translation: AAH21255.2.
BC101518 mRNA. Translation: AAI01519.1.
BC101520 mRNA. Translation: AAI01521.1.
AF034800 mRNA. Translation: AAC26101.1.
CCDSiCCDS12758.1. [O75145-1]
RefSeqiNP_003651.1. NM_003660.3. [O75145-1]
XP_006723513.1. XM_006723450.1. [O75145-2]
UniGeneiHs.413748.
Hs.604638.

3D structure databases

ProteinModelPortaliO75145.
SMRiO75145. Positions 812-1115.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi114111. 9 interactions.
IntActiO75145. 2 interactions.
MINTiMINT-3001008.
STRINGi9606.ENSP00000335614.

PTM databases

PhosphoSiteiO75145.

Polymorphism and mutation databases

BioMutaiPPFIA3.

Proteomic databases

MaxQBiO75145.
PaxDbiO75145.
PRIDEiO75145.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000334186; ENSP00000335614; ENSG00000177380.
ENST00000602351; ENSP00000473622; ENSG00000177380. [O75145-2]
GeneIDi8541.
KEGGihsa:8541.
UCSCiuc002pmr.3. human. [O75145-1]
uc002pms.3. human. [O75145-2]

Organism-specific databases

CTDi8541.
GeneCardsiGC19P049622.
HGNCiHGNC:9247. PPFIA3.
HPAiHPA043567.
HPA050340.
MIMi603144. gene.
neXtProtiNX_O75145.
PharmGKBiPA33568.
HUGEiSearch...
GenAtlasiSearch...

Phylogenomic databases

eggNOGiNOG322697.
GeneTreeiENSGT00760000119138.
HOGENOMiHOG000017513.
HOVERGENiHBG052330.
InParanoidiO75145.
OMAiSKRQEWE.
OrthoDBiEOG7T7GS7.
PhylomeDBiO75145.
TreeFamiTF314207.

Enzyme and pathway databases

ReactomeiREACT_12591. Glutamate Neurotransmitter Release Cycle.
REACT_15293. Dopamine Neurotransmitter Release Cycle.
REACT_15309. Acetylcholine Neurotransmitter Release Cycle.
REACT_15418. Norepinephrine Neurotransmitter Release Cycle.
REACT_15425. Serotonin Neurotransmitter Release Cycle.

Miscellaneous databases

ChiTaRSiPPFIA3. human.
GenomeRNAii8541.
NextBioi31992.
PROiO75145.
SOURCEiSearch...

Gene expression databases

BgeeiO75145.
CleanExiHS_PPFIA3.
ExpressionAtlasiO75145. baseline and differential.
GenevisibleiO75145. HS.

Family and domain databases

Gene3Di1.10.150.50. 2 hits.
InterProiIPR029515. Liprin.
IPR030440. PPFIA3.
IPR001660. SAM.
IPR013761. SAM/pointed.
IPR011510. SAM_2.
IPR021129. SAM_type1.
[Graphical view]
PANTHERiPTHR12587. PTHR12587. 1 hit.
PTHR12587:SF4. PTHR12587:SF4. 1 hit.
PfamiPF00536. SAM_1. 2 hits.
PF07647. SAM_2. 1 hit.
[Graphical view]
SMARTiSM00454. SAM. 3 hits.
[Graphical view]
SUPFAMiSSF47769. SSF47769. 3 hits.
PROSITEiPS50105. SAM_DOMAIN. 3 hits.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Prediction of the coding sequences of unidentified human genes. X. The complete sequences of 100 new cDNA clones from brain which can code for large proteins in vitro."
    Ishikawa K., Nagase T., Suyama M., Miyajima N., Tanaka A., Kotani H., Nomura N., Ohara O.
    DNA Res. 5:169-176(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
    Tissue: Brain.
  2. "Construction of expression-ready cDNA clones for KIAA genes: manual curation of 330 KIAA cDNA clones."
    Nakajima D., Okazaki N., Yamakawa H., Kikuno R., Ohara O., Nagase T.
    DNA Res. 9:99-106(2002) [PubMed] [Europe PMC] [Abstract]
    Cited for: SEQUENCE REVISION.
  3. "Complete sequencing and characterization of 21,243 full-length human cDNAs."
    Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S.
    , Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S.
    Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1), NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 152-1194 (ISOFORM 2), VARIANT SER-563.
    Tissue: Brain.
  4. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA], VARIANT SER-563.
  5. "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
    The MGC Project Team
    Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1), NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 909-1194 (ISOFORM 2), VARIANT SER-563.
    Tissue: Brain and Muscle.
  6. "Liprins, a family of LAR transmembrane protein-tyrosine phosphatase-interacting proteins."
    Serra-Pages C., Medley Q.G., Tang M., Hart A., Streuli M.
    J. Biol. Chem. 273:15611-15620(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 752-1194 (ISOFORM 1), TISSUE SPECIFICITY, FUNCTION, INTERACTION WITH PTPRD; PTPRF AND PTPRS.
  7. Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
    Tissue: Cervix carcinoma.
  8. "Lys-N and trypsin cover complementary parts of the phosphoproteome in a refined SCX-based approach."
    Gauci S., Helbig A.O., Slijper M., Krijgsveld J., Heck A.J., Mohammed S.
    Anal. Chem. 81:4493-4501(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
  9. "Quantitative phosphoproteomic analysis of T cell receptor signaling reveals system-wide modulation of protein-protein interactions."
    Mayya V., Lundgren D.H., Hwang S.-I., Rezaul K., Wu L., Eng J.K., Rodionov V., Han D.K.
    Sci. Signal. 2:RA46-RA46(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-17; SER-207; THR-714 AND THR-718, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
    Tissue: Leukemic T-cell.
  10. Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].

Entry informationi

Entry nameiLIPA3_HUMAN
AccessioniPrimary (citable) accession number: O75145
Secondary accession number(s): A8K142
, Q3MJA0, Q9H8B5, Q9UEW4
Entry historyi
Integrated into UniProtKB/Swiss-Prot: February 16, 2004
Last sequence update: February 16, 2004
Last modified: July 22, 2015
This is version 127 of the entry and version 3 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. Human chromosome 19
    Human chromosome 19: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.