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Protein

Membrane-associated phosphatidylinositol transfer protein 1

Gene

PITPNM1

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

Functioni

Regulates RHOA activity, and plays a role in cytoskeleton remodeling. Necessary for normal completion of cytokinesis. Plays a role in maintaining normal diacylglycerol levels in the Golgi apparatus. Binds phosphatidyl inositol phosphates (in vitro). May catalyze the transfer of phosphatidylinositol and phosphatidylcholine between membranes (By similarity). Necessary for maintaining the normal structure of the endoplasmic reticulum and the Golgi apparatus. Required for protein export from the endoplasmic reticulum and the Golgi. Binds calcium ions.By similarity4 Publications

GO - Molecular functioni

  1. metal ion binding Source: UniProtKB-KW
  2. phosphatidylinositol transporter activity Source: ProtInc

GO - Biological processi

  1. brain development Source: ProtInc
  2. lipid metabolic process Source: ProtInc
  3. phospholipid transport Source: GOC
  4. phototransduction Source: ProtInc
  5. protein transport Source: UniProtKB-KW
Complete GO annotation...

Keywords - Biological processi

Protein transport, Transport

Keywords - Ligandi

Calcium, Metal-binding

Names & Taxonomyi

Protein namesi
Recommended name:
Membrane-associated phosphatidylinositol transfer protein 1
Alternative name(s):
Drosophila retinal degeneration B homolog
Phosphatidylinositol transfer protein, membrane-associated 1
Short name:
PITPnm 1
Pyk2 N-terminal domain-interacting receptor 2
Short name:
NIR-2
Gene namesi
Name:PITPNM1
Synonyms:DRES9, NIR2, PITPNM
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640 Componenti: Chromosome 11

Organism-specific databases

HGNCiHGNC:9003. PITPNM1.

Subcellular locationi

Cytoplasm. Golgi apparatusGolgi stack membrane; Peripheral membrane protein. Endoplasmic reticulum membrane; Peripheral membrane protein. Lipid droplet. Cleavage furrow. Midbody
Note: Peripheral membrane protein associated with Golgi stacks in interphase cells. A minor proportion is associated with the endoplasmic reticulum. Associated with lipid droplets. Dissociates from the Golgi early on in mitosis and localizes to the cleavage furrow and midbody during cytokinesis.

GO - Cellular componenti

  1. cleavage furrow Source: UniProtKB-SubCell
  2. cytoplasm Source: HPA
  3. endoplasmic reticulum membrane Source: UniProtKB-SubCell
  4. Golgi cisterna membrane Source: UniProtKB-SubCell
  5. lipid particle Source: UniProtKB-SubCell
  6. membrane Source: ProtInc
  7. midbody Source: UniProtKB-SubCell
Complete GO annotation...

Keywords - Cellular componenti

Cytoplasm, Endoplasmic reticulum, Golgi apparatus, Lipid droplet, Membrane

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi59 – 591T → A: Prevents association with lipid droplets. 1 Publication
Mutagenesisi59 – 591T → E: Causes association with lipid droplets. 1 Publication
Mutagenesisi287 – 2871T → A: Slightly reduced phosphorylation. Strongly reduced phosphorylation; when associated with A-794 or A-389. Loss of threonine phosphorylation; when associated with A-389; A-793 and A-1222. 1 Publication
Mutagenesisi300 – 3001S → A: No effect on phosphorylation. 1 Publication
Mutagenesisi326 – 3261S → A: No effect on phosphorylation. 1 Publication
Mutagenesisi349 – 3535EFFDA → ALLAG: Loss of interaction with VAPB. 1 Publication
Mutagenesisi382 – 3821S → A: Strongly reduced phosphorylation. 1 Publication
Mutagenesisi389 – 3891T → A: No detectable effect on phosphorylation; when associated with A-793 and A-1222. Strongly reduced phosphorylation; when associated with A-287. Loss of threonine phosphorylation; when associated with A-287; A-794 and A-1222. 1 Publication
Mutagenesisi794 – 7941T → A: No detectable effect on phosphorylation; when associated with A-389 and A-1222. Strongly reduced phosphorylation; when associated with A-287. Loss of threonine phosphorylation; when associated with A-287; A-389 and A-1222. 1 Publication
Mutagenesisi896 – 8961S → A: Reduced phosphorylation. 1 Publication
Mutagenesisi1223 – 12231T → A: No detectable effect on phosphorylation; when associated with A-389 and A-793. Loss of threonine phosphorylation; when associated with A-287; A-389 and A-794. 1 Publication

Organism-specific databases

PharmGKBiPA33337.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 12441244Membrane-associated phosphatidylinositol transfer protein 1PRO_0000232738Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei59 – 591Phosphothreonine1 Publication
Modified residuei287 – 2871Phosphothreonine; by CDK11 Publication
Modified residuei382 – 3821Phosphoserine; by CDK11 Publication
Modified residuei600 – 6001Phosphoserine1 Publication
Modified residuei621 – 6211Phosphoserine1 Publication
Modified residuei896 – 8961Phosphoserine1 Publication

Post-translational modificationi

Phosphorylated on multiple sites by CDK1 at the onset of mitosis. Phosphorylation facilitates dissociation from the Golgi complex and is required for interaction with PLK1.
Phosphorylated on threonine residues upon treatment with oleic acid.
Phosphorylated on tyrosine residues by PTK2B.

Keywords - PTMi

Phosphoprotein

Proteomic databases

MaxQBiO00562.
PaxDbiO00562.
PRIDEiO00562.

PTM databases

PhosphoSiteiO00562.

Expressioni

Tissue specificityi

Ubiquitous.1 Publication

Gene expression databases

BgeeiO00562.
CleanExiHS_PITPNM1.
ExpressionAtlasiO00562. baseline and differential.
GenevestigatoriO00562.

Organism-specific databases

HPAiHPA060227.

Interactioni

Subunit structurei

Interacts with PIK4CA (By similarity). Interacts with PTK2B via its C-terminus. Interacts with RHOA. Has higher affinity for the inactive, GDP-bound form of RHOA. The CDK1-phosphorylated form interacts with PLK1. Interacts with VAPB.By similarity4 Publications

Protein-protein interaction databases

BioGridi114965. 3 interactions.
IntActiO00562. 2 interactions.
STRINGi9606.ENSP00000348772.

Structurei

3D structure databases

ProteinModelPortaliO00562.
SMRiO00562. Positions 1-254.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini686 – 880195DDHDPROSITE-ProRule annotationAdd
BLAST

Compositional bias

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Compositional biasi310 – 31910Poly-Ser

Sequence similaritiesi

Contains 1 DDHD domain.PROSITE-ProRule annotation

Phylogenomic databases

eggNOGiCOG5083.
GeneTreeiENSGT00760000119216.
HOGENOMiHOG000294231.
HOVERGENiHBG052733.
InParanoidiO00562.
OMAiMQNIARD.
OrthoDBiEOG7NW69J.
PhylomeDBiO00562.
TreeFamiTF312967.

Family and domain databases

Gene3Di3.30.530.20. 1 hit.
3.40.50.1000. 1 hit.
InterProiIPR004177. DDHD.
IPR023214. HAD-like_dom.
IPR013209. LNS2.
IPR001666. PI_transfer.
IPR023393. START-like_dom.
[Graphical view]
PANTHERiPTHR10658. PTHR10658. 1 hit.
PfamiPF02862. DDHD. 1 hit.
PF02121. IP_trans. 1 hit.
PF08235. LNS2. 1 hit.
[Graphical view]
PRINTSiPR00391. PITRANSFER.
SMARTiSM00775. LNS2. 1 hit.
[Graphical view]
SUPFAMiSSF56784. SSF56784. 1 hit.
PROSITEiPS51043. DDHD. 1 hit.
[Graphical view]

Sequences (2)i

Sequence statusi: Complete.

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

Isoform 1 (identifier: O00562-1) [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
MLIKEYHILL PMSLDEYQVA QLYMIQKKSR EESSGEGSGV EILANRPYTD
60 70 80 90 100
GPGGSGQYTH KVYHVGSHIP GWFRALLPKA ALQVEEESWN AYPYTRTRYT
110 120 130 140 150
CPFVEKFSIE IETYYLPDGG QQPNVFNLSG AERRQRILDT IDIVRDAVAP
160 170 180 190 200
GEYKAEEDPR LYHSVKTGRG PLSDDWARTA AQTGPLMCAY KLCKVEFRYW
210 220 230 240 250
GMQAKIEQFI HDVGLRRVML RAHRQAWCWQ DEWTELSMAD IRALEEETAR
260 270 280 290 300
MLAQRMAKCN TGSEGSEAQP PGKPSTEARS AASNTGTPDG PEAPPGPDAS
310 320 330 340 350
PDASFGKQWS SSSRSSYSSQ HGGAVSPQSL SEWRMQNIAR DSENSSEEEF
360 370 380 390 400
FDAHEGFSDS EEVFPKEMTK WNSNDFIDAF ASPVEAEGTP EPGAEAAKGI
410 420 430 440 450
EDGAQAPRDS EGLDGAGELG AEACAVHALF LILHSGNILD SGPGDANSKQ
460 470 480 490 500
ADVQTLSSAF EAVTRIHFPE ALGHVALRLV PCPPICAAAY ALVSNLSPYS
510 520 530 540 550
HDGDSLSRSQ DHIPLAALPL LATSSSRYQG AVATVIARTN QAYSAFLRSP
560 570 580 590 600
EGAGFCGQVA LIGDGVGGIL GFDALCHSAN AGTGSRGSSR RGSMNNELLS
610 620 630 640 650
PEFGPVRDPL ADGVEGLGRG SPEPSALPPQ RIPSDMASPE PEGSQNSLQA
660 670 680 690 700
APATTSSWEP RRASTAFCPP AASSEAPDGP SSTARLDFKV SGFFLFGSPL
710 720 730 740 750
GLVLALRKTV MPALEAAQMR PACEQIYNLF HAADPCASRL EPLLAPKFQA
760 770 780 790 800
IAPLTVPRYQ KFPLGDGSSL LLADTLQTHS SLFLEELEML VPSTPTSTSG
810 820 830 840 850
AFWKGSELAT DPPAQPAAPS TTSEVVKILE RWWGTKRIDY SLYCPEALTA
860 870 880 890 900
FPTVTLPHLF HASYWESADV VAFILRQVIE KERPQLAECE EPSIYSPAFP
910 920 930 940 950
REKWQRKRTQ VKIRNVTSNH RASDTVVCEG RPQVLSGRFM YGPLDVVTLT
960 970 980 990 1000
GEKVDVYIMT QPLSGKWIHF GTEVTNSSGR LTFPVPPERA LGIGVYPVRM
1010 1020 1030 1040 1050
VVRGDHTYAE CCLTVVARGT EAVVFSIDGS FTASVSIMGS DPKVRAGAVD
1060 1070 1080 1090 1100
VVRHWQDSGY LIVYVTGRPD MQKHRVVAWL SQHNFPHGVV SFCDGLTHDP
1110 1120 1130 1140 1150
LRQKAMFLQS LVQEVELNIV AGYGSPKDVA VYAALGLSPS QTYIVGRAVR
1160 1170 1180 1190 1200
KLQAQCQFLS DGYVAHLGQL EAGSHSHASS GPPRAALGKS SYGVAAPVDF
1210 1220 1230 1240
LRKQSQLLRS RGPSQAEREG PGTPPTTLAR GKARSISLKL DSEE
Length:1,244
Mass (Da):134,848
Last modified:October 30, 2006 - v4
Checksum:iF4B66E98B085E9C0
GO
Isoform 2 (identifier: O00562-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     716-716: Missing.

Show »
Length:1,243
Mass (Da):134,777
Checksum:i6262539C57A79DA6
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti931 – 9311R → P in AAK01444 (PubMed:10022914).Curated
Sequence conflicti1034 – 10341S → G in AAR06909 (PubMed:15627748).Curated
Sequence conflicti1116 – 11161E → G in CAA67224 (PubMed:9680295).Curated
Sequence conflicti1133 – 11331A → T in CAA67224 (PubMed:9680295).Curated

Alternative sequence

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Alternative sequencei716 – 7161Missing in isoform 2. 2 PublicationsVSP_021157

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X98654 mRNA. Translation: CAA67224.1.
AF334584 mRNA. Translation: AAK01444.1.
AY429102 mRNA. Translation: AAR06909.1.
AP001184 Genomic DNA. No translation available.
CH471076 Genomic DNA. Translation: EAW74638.1.
BC022230 mRNA. Translation: AAH22230.1.
CCDSiCCDS31620.1. [O00562-1]
CCDS44659.1. [O00562-2]
RefSeqiNP_001124320.1. NM_001130848.1. [O00562-2]
NP_004901.2. NM_004910.2. [O00562-1]
UniGeneiHs.372295.

Genome annotation databases

EnsembliENST00000356404; ENSP00000348772; ENSG00000110697. [O00562-1]
ENST00000436757; ENSP00000398787; ENSG00000110697. [O00562-2]
ENST00000534749; ENSP00000437286; ENSG00000110697. [O00562-1]
GeneIDi9600.
KEGGihsa:9600.
UCSCiuc001olx.3. human. [O00562-1]
uc001olz.3. human. [O00562-2]

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X98654 mRNA. Translation: CAA67224.1.
AF334584 mRNA. Translation: AAK01444.1.
AY429102 mRNA. Translation: AAR06909.1.
AP001184 Genomic DNA. No translation available.
CH471076 Genomic DNA. Translation: EAW74638.1.
BC022230 mRNA. Translation: AAH22230.1.
CCDSiCCDS31620.1. [O00562-1]
CCDS44659.1. [O00562-2]
RefSeqiNP_001124320.1. NM_001130848.1. [O00562-2]
NP_004901.2. NM_004910.2. [O00562-1]
UniGeneiHs.372295.

3D structure databases

ProteinModelPortaliO00562.
SMRiO00562. Positions 1-254.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi114965. 3 interactions.
IntActiO00562. 2 interactions.
STRINGi9606.ENSP00000348772.

Chemistry

ChEMBLiCHEMBL1764937.

PTM databases

PhosphoSiteiO00562.

Proteomic databases

MaxQBiO00562.
PaxDbiO00562.
PRIDEiO00562.

Protocols and materials databases

DNASUi9600.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000356404; ENSP00000348772; ENSG00000110697. [O00562-1]
ENST00000436757; ENSP00000398787; ENSG00000110697. [O00562-2]
ENST00000534749; ENSP00000437286; ENSG00000110697. [O00562-1]
GeneIDi9600.
KEGGihsa:9600.
UCSCiuc001olx.3. human. [O00562-1]
uc001olz.3. human. [O00562-2]

Organism-specific databases

CTDi9600.
GeneCardsiGC11M067260.
HGNCiHGNC:9003. PITPNM1.
HPAiHPA060227.
MIMi608794. gene.
neXtProtiNX_O00562.
PharmGKBiPA33337.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiCOG5083.
GeneTreeiENSGT00760000119216.
HOGENOMiHOG000294231.
HOVERGENiHBG052733.
InParanoidiO00562.
OMAiMQNIARD.
OrthoDBiEOG7NW69J.
PhylomeDBiO00562.
TreeFamiTF312967.

Miscellaneous databases

ChiTaRSiPITPNM1. human.
GeneWikiiPITPNM1.
GenomeRNAii9600.
NextBioi36015.
PROiO00562.
SOURCEiSearch...

Gene expression databases

BgeeiO00562.
CleanExiHS_PITPNM1.
ExpressionAtlasiO00562. baseline and differential.
GenevestigatoriO00562.

Family and domain databases

Gene3Di3.30.530.20. 1 hit.
3.40.50.1000. 1 hit.
InterProiIPR004177. DDHD.
IPR023214. HAD-like_dom.
IPR013209. LNS2.
IPR001666. PI_transfer.
IPR023393. START-like_dom.
[Graphical view]
PANTHERiPTHR10658. PTHR10658. 1 hit.
PfamiPF02862. DDHD. 1 hit.
PF02121. IP_trans. 1 hit.
PF08235. LNS2. 1 hit.
[Graphical view]
PRINTSiPR00391. PITRANSFER.
SMARTiSM00775. LNS2. 1 hit.
[Graphical view]
SUPFAMiSSF56784. SSF56784. 1 hit.
PROSITEiPS51043. DDHD. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "A mammalian homologue of the Drosophila retinal degeneration B gene: implications for the evolution of phototransduction mechanisms."
    Rubboli F., Bulfone A., Bogni S., Marchitiello A., Zollo M., Borsani G., Ballabio A., Banfi S.
    Genes Funct. 1:205-213(1996) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
  2. "Identification of a novel family of targets of PYK2 related to Drosophila retinal degeneration B (rdgB) protein."
    Lev S., Hernandez J., Martinez R., Chen A., Plowman G., Schlessinger J.
    Mol. Cell. Biol. 19:2278-2288(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), FUNCTION, CALCIUM-BINDING, INTERACTION WITH PTK2B, PHOSPHORYLATION, TISSUE SPECIFICITY.
    Tissue: Brain.
  3. "Chromosomal localization, genomic organization and evolution of the genes encoding human phosphatidylinositol transfer protein membrane-associated (PITPNM) 1, 2 and 3."
    Ocaka L., Spalluto C., Wilson D.I., Hunt D.M., Halford S.
    Cytogenet. Genome Res. 108:293-302(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2).
  4. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
  5. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
  6. "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(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2).
    Tissue: Duodenum.
  7. "Targeting of Nir2 to lipid droplets is regulated by a specific threonine residue within its PI-transfer domain."
    Litvak V., Shaul Y.D., Shulewitz M., Amarilio R., Carmon S., Lev S.
    Curr. Biol. 12:1513-1518(2001) [PubMed] [Europe PMC] [Abstract]
    Cited for: SUBCELLULAR LOCATION, MUTAGENESIS OF THR-59, PHOSPHORYLATION AT THR-59.
  8. Cited for: FUNCTION, INTERACTION WITH RHOA.
  9. "Mitotic phosphorylation of the peripheral Golgi protein Nir2 by Cdk1 provides a docking mechanism for Plk1 and affects cytokinesis completion."
    Litvak V., Argov R., Dahan N., Ramachandran S., Amarilio R., Shainskaya A., Lev S.
    Mol. Cell 14:319-330(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION AT THR-287; SER-382 AND SER-896, IDENTIFICATION BY MASS SPECTROMETRY, MUTAGENESIS OF THR-287; SER-300; SER-326; SER-382; THR-389; THR-794; SER-896 AND THR-1223, INTERACTION WITH CDK1 AND PLK1, SUBCELLULAR LOCATION.
  10. "Differential regulation of endoplasmic reticulum structure through VAP-Nir protein interaction."
    Amarilio R., Ramachandran S., Sabanay H., Lev S.
    J. Biol. Chem. 280:5934-5944(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, INTERACTION WITH VAPB, MUTAGENESIS OF 349-GLU--ALA-353.
  11. "Maintenance of the diacylglycerol level in the Golgi apparatus by the Nir2 protein is critical for Golgi secretory function."
    Litvak V., Dahan N., Ramachandran S., Sabanay H., Lev S.
    Nat. Cell Biol. 7:225-234(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION.
  12. "An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome."
    Bian Y., Song C., Cheng K., Dong M., Wang F., Huang J., Sun D., Wang L., Ye M., Zou H.
    J. Proteomics 96:253-262(2013) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-600 AND SER-621, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
    Tissue: Liver.

Entry informationi

Entry nameiPITM1_HUMAN
AccessioniPrimary (citable) accession number: O00562
Secondary accession number(s): A6NME4
, Q6T7X3, Q8TBN3, Q9BZ73
Entry historyi
Integrated into UniProtKB/Swiss-Prot: April 17, 2006
Last sequence update: October 30, 2006
Last modified: March 3, 2015
This is version 114 of the entry and version 4 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 11
    Human chromosome 11: entries, gene names and cross-references to MIM
  2. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  3. 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.