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Protein

Sterile alpha and TIR motif-containing protein 1

Gene

Sarm1

Organism
Mus musculus (Mouse)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Negative regulator of MYD88- and TRIF-dependent toll-like receptor signaling pathway which plays a pivotal role in activating axonal degeneration following injury. Promotes Wallerian degeneration an injury-induced axonal death pathway which involves degeneration of an axon distal to the injury site. Can activate neuronal death in response to stress. Regulates dendritic arborization through the MAPK4-JNK pathway. Involved in innate immune response. Inhibits both TICAM1/TRIF- and MYD88-dependent activation of JUN/AP-1, TRIF-dependent activation of NF-kappa-B and IRF3, and the phosphorylation of MAPK14/p38. Can restrict West Nile virus (WNV) pathogenesis.4 Publications

GO - Biological processi

  • innate immune response Source: UniProtKB-KW
  • regulation of apoptotic process Source: MGI
  • regulation of dendrite morphogenesis Source: UniProtKB
  • regulation of neuron death Source: UniProtKB
  • response to glucose Source: MGI
  • signal transduction Source: InterPro
Complete GO annotation...

Keywords - Biological processi

Differentiation, Immunity, Innate immunity, Neurogenesis

Names & Taxonomyi

Protein namesi
Recommended name:
Sterile alpha and TIR motif-containing protein 1
Alternative name(s):
Tir-1 homolog
Short name:
MyD88-5
Gene namesi
Name:Sarm1
Synonyms:Kiaa0524
OrganismiMus musculus (Mouse)
Taxonomic identifieri10090 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeMusMus
Proteomesi
  • UP000000589 Componenti: Chromosome 11

Organism-specific databases

MGIiMGI:2136419. Sarm1.

Subcellular locationi

GO - Cellular componenti

  • axon Source: UniProtKB-SubCell
  • cell junction Source: UniProtKB-KW
  • cytoplasm Source: UniProtKB
  • dendrite Source: UniProtKB
  • extrinsic component of mitochondrial outer membrane Source: MGI
  • microtubule Source: UniProtKB
  • microtubule cytoskeleton Source: MGI
  • mitochondrion Source: UniProtKB
  • synapse Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Cell junction, Cell projection, Cytoplasm, Mitochondrion, Synapse

Pathology & Biotechi

Disruption phenotypei

Severed Sarm1 null axons are able to persist up to 72 hrs after axotomy, whereas wild-type axons degenerate within 8 hrs. Similarly, axons appear to be protected from degeneration in a sciatic nerve lesion model, lasting up to 14 days compared with 3 days for wild type.1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Transit peptidei1 – 2727MitochondrionBy similarityAdd
BLAST
Chaini28 – 724697Sterile alpha and TIR motif-containing protein 1PRO_0000097590Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei548 – 5481PhosphoserineCombined sources
Modified residuei558 – 5581PhosphoserineCombined sources

Keywords - PTMi

Phosphoprotein

Proteomic databases

MaxQBiQ6PDS3.
PRIDEiQ6PDS3.

PTM databases

iPTMnetiQ6PDS3.
PhosphoSiteiQ6PDS3.

Expressioni

Tissue specificityi

Widely expressed in the brain and neurons (at protein level).1 Publication

Gene expression databases

BgeeiQ6PDS3.
GenevisibleiQ6PDS3. MM.

Interactioni

Subunit structurei

Interacts with TICAM1/TRIF and thereby interferes with TICAM1/TRIF function (By similarity). Interacts with SDC2 (via cytoplasmic domain) and MAPK10/JNK3.By similarity2 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
CCDC47Q96A332EBI-6117196,EBI-720151From a different organism.
GHITMQ9H3K22EBI-6117196,EBI-2868909From a different organism.
IRAK2O431872EBI-6117196,EBI-447733From a different organism.
NLRX1Q86UT62EBI-6117196,EBI-3893071From a different organism.
STT3AP469772EBI-6117196,EBI-719212From a different organism.

Protein-protein interaction databases

BioGridi231917. 1 interaction.
IntActiQ6PDS3. 10 interactions.
MINTiMINT-4997481.

Structurei

3D structure databases

ProteinModelPortaliQ6PDS3.
SMRiQ6PDS3. Positions 111-394, 413-475.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini412 – 47665SAM 1PROSITE-ProRule annotationAdd
BLAST
Domaini486 – 54863SAM 2PROSITE-ProRule annotationAdd
BLAST
Domaini559 – 65799TIRAdd
BLAST

Sequence similaritiesi

Contains 2 SAM (sterile alpha motif) domains.PROSITE-ProRule annotation
Contains 1 TIR domain.Curated

Keywords - Domaini

Repeat, Transit peptide

Phylogenomic databases

GeneTreeiENSGT00390000004155.
HOGENOMiHOG000008460.
HOVERGENiHBG079166.
InParanoidiQ6PDS3.
OMAiAFYLCVE.
OrthoDBiEOG7Z3F3N.
PhylomeDBiQ6PDS3.
TreeFamiTF315263.

Family and domain databases

Gene3Di1.10.150.50. 2 hits.
1.25.10.10. 1 hit.
3.40.50.10140. 1 hit.
InterProiIPR011989. ARM-like.
IPR016024. ARM-type_fold.
IPR001660. SAM.
IPR013761. SAM/pointed.
IPR000157. TIR_dom.
[Graphical view]
PfamiPF07647. SAM_2. 2 hits.
PF13676. TIR_2. 1 hit.
[Graphical view]
SMARTiSM00454. SAM. 2 hits.
SM00255. TIR. 1 hit.
[Graphical view]
SUPFAMiSSF47769. SSF47769. 2 hits.
SSF48371. SSF48371. 1 hit.
SSF52200. SSF52200. 1 hit.
PROSITEiPS50105. SAM_DOMAIN. 2 hits.
[Graphical view]

Sequences (4)i

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

This entry describes 4 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: Q6PDS3-1) [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
MVLTLLFSAY KLCRFFTMSG PRPGADRLTV PGPDRSGGAS PWWAAGGRGS
60 70 80 90 100
REVSPGVGTE VQGALERSLP ELQQALSELK QASAARAVGA GLAEVFQLVE
110 120 130 140 150
EAWLLPAVGR EVAQGLCDAI RLDGGLDLLL RLLQAPELET RVQAARLLEQ
160 170 180 190 200
ILVAENRDRV ARIGLGVILN LAKEREPVEL ARSVAGILEH MFKHSEETCQ
210 220 230 240 250
RLVAAGGLDA VLYWCRRTDP ALLRHCALAL ANCALHGGQT VQRCMVEKRA
260 270 280 290 300
AEWLFPLAFS KEDELLRLHA CLAVAVLATN KEVEREVEHS GTLALVEPLV
310 320 330 340 350
ASLDPGRFAR CLVDASDTSQ GRGPDDLQSL VLLLDSSRLE AQCIGAFYLC
360 370 380 390 400
AEAAIKSLQG KTKVFSDIGA IQSLKRLVSY STNGTTSALA KRALRLLGEE
410 420 430 440 450
VPRRILPCVA SWKEAEVQTW LQQIGFSQYC ENFREQQVDG DLLLRLTDEE
460 470 480 490 500
LQTDLGMKSS ITRKRFFREL TELKTFASYA TCDRSNLADW LGSLDPRFRQ
510 520 530 540 550
YTYGLVSCGL DRSLLHRVSE QQLLEDCGIR LGVHRTRILS AAREMLHSPL
560 570 580 590 600
PCTGGKLSGD TPDVFISYRR NSGSQLASLL KVHLQLHGFS VFIDVEKLEA
610 620 630 640 650
GKFEDKLIQS VIAARNFVLV LSAGALDKCM QDHDCKDWVH KEIVTALSCG
660 670 680 690 700
KNIVPIIDGF EWPEPQALPE DMQAVLTFNG IKWSHEYQEA TIEKIIRFLQ
710 720
GRPSQDSSAG SDTSLEGATP MGLP
Length:724
Mass (Da):79,606
Last modified:July 5, 2004 - v1
Checksum:i9A5BF03ED22E6102
GO
Isoform 2 (identifier: Q6PDS3-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     435-439: Missing.

Note: No experimental confirmation available.
Show »
Length:719
Mass (Da):79,007
Checksum:i08843BA13C0DD69F
GO
Isoform 3 (identifier: Q6PDS3-3) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     543-543: R → RGHFAQTGLRSLRRPSLHDDGPRDKQWGRATLTSMSLSLAP

Show »
Length:764
Mass (Da):84,006
Checksum:iD76542F538604CF8
GO
Isoform 4 (identifier: Q6PDS3-4) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-536: Missing.
     537-543: RILSAAR → MSLSLAP

Note: No experimental confirmation available.
Show »
Length:188
Mass (Da):20,594
Checksum:i35C1A626B521791D
GO

Sequence cautioni

The sequence BAD32242.1 differs from that shown. Reason: Erroneous initiation. Curated
The sequence CAI25546.1 differs from that shown. Reason: Erroneous gene model prediction. Curated

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti61 – 611V → A in AAR17521 (Ref. 1) Curated

Alternative sequence

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Alternative sequencei1 – 536536Missing in isoform 4. CuratedVSP_013606Add
BLAST
Alternative sequencei435 – 4395Missing in isoform 2. 1 PublicationVSP_013604
Alternative sequencei537 – 5437RILSAAR → MSLSLAP in isoform 4. CuratedVSP_013607
Alternative sequencei543 – 5431R → RGHFAQTGLRSLRRPSLHDD GPRDKQWGRATLTSMSLSLA P in isoform 3. 1 PublicationVSP_013605

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY444167 mRNA. Translation: AAR17521.1.
AK172964 Transcribed RNA. Translation: BAD32242.1. Different initiation.
AK044113 mRNA. Translation: BAC31784.1.
AL591177 Genomic DNA. Translation: CAI25544.1.
AL591177 Genomic DNA. Translation: CAI25545.1.
AL591177 Genomic DNA. Translation: CAI25546.1. Sequence problems.
BC058534 mRNA. Translation: AAH58534.1.
BC080850 mRNA. Translation: AAH80850.1.
CCDSiCCDS25105.1. [Q6PDS3-1]
CCDS48857.1. [Q6PDS3-3]
RefSeqiNP_001161993.1. NM_001168521.1. [Q6PDS3-3]
NP_766383.2. NM_172795.3. [Q6PDS3-1]
UniGeneiMm.210332.

Genome annotation databases

EnsembliENSMUST00000061174; ENSMUSP00000051059; ENSMUSG00000050132. [Q6PDS3-1]
ENSMUST00000108287; ENSMUSP00000103922; ENSMUSG00000050132. [Q6PDS3-3]
GeneIDi237868.
KEGGimmu:237868.
UCSCiuc007kjh.2. mouse. [Q6PDS3-4]
uc007kji.2. mouse. [Q6PDS3-1]
uc007kjj.2. mouse. [Q6PDS3-3]

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY444167 mRNA. Translation: AAR17521.1.
AK172964 Transcribed RNA. Translation: BAD32242.1. Different initiation.
AK044113 mRNA. Translation: BAC31784.1.
AL591177 Genomic DNA. Translation: CAI25544.1.
AL591177 Genomic DNA. Translation: CAI25545.1.
AL591177 Genomic DNA. Translation: CAI25546.1. Sequence problems.
BC058534 mRNA. Translation: AAH58534.1.
BC080850 mRNA. Translation: AAH80850.1.
CCDSiCCDS25105.1. [Q6PDS3-1]
CCDS48857.1. [Q6PDS3-3]
RefSeqiNP_001161993.1. NM_001168521.1. [Q6PDS3-3]
NP_766383.2. NM_172795.3. [Q6PDS3-1]
UniGeneiMm.210332.

3D structure databases

ProteinModelPortaliQ6PDS3.
SMRiQ6PDS3. Positions 111-394, 413-475.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi231917. 1 interaction.
IntActiQ6PDS3. 10 interactions.
MINTiMINT-4997481.

PTM databases

iPTMnetiQ6PDS3.
PhosphoSiteiQ6PDS3.

Proteomic databases

MaxQBiQ6PDS3.
PRIDEiQ6PDS3.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENSMUST00000061174; ENSMUSP00000051059; ENSMUSG00000050132. [Q6PDS3-1]
ENSMUST00000108287; ENSMUSP00000103922; ENSMUSG00000050132. [Q6PDS3-3]
GeneIDi237868.
KEGGimmu:237868.
UCSCiuc007kjh.2. mouse. [Q6PDS3-4]
uc007kji.2. mouse. [Q6PDS3-1]
uc007kjj.2. mouse. [Q6PDS3-3]

Organism-specific databases

CTDi23098.
MGIiMGI:2136419. Sarm1.
RougeiSearch...

Phylogenomic databases

GeneTreeiENSGT00390000004155.
HOGENOMiHOG000008460.
HOVERGENiHBG079166.
InParanoidiQ6PDS3.
OMAiAFYLCVE.
OrthoDBiEOG7Z3F3N.
PhylomeDBiQ6PDS3.
TreeFamiTF315263.

Miscellaneous databases

NextBioi383536.
PROiQ6PDS3.
SOURCEiSearch...

Gene expression databases

BgeeiQ6PDS3.
GenevisibleiQ6PDS3. MM.

Family and domain databases

Gene3Di1.10.150.50. 2 hits.
1.25.10.10. 1 hit.
3.40.50.10140. 1 hit.
InterProiIPR011989. ARM-like.
IPR016024. ARM-type_fold.
IPR001660. SAM.
IPR013761. SAM/pointed.
IPR000157. TIR_dom.
[Graphical view]
PfamiPF07647. SAM_2. 2 hits.
PF13676. TIR_2. 1 hit.
[Graphical view]
SMARTiSM00454. SAM. 2 hits.
SM00255. TIR. 1 hit.
[Graphical view]
SUPFAMiSSF47769. SSF47769. 2 hits.
SSF48371. SSF48371. 1 hit.
SSF52200. SSF52200. 1 hit.
PROSITEiPS50105. SAM_DOMAIN. 2 hits.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "SARM1 isoforms nucleotide sequence."
    Bousson J.-C., Casteran C., Tiraby G.
    Submitted (OCT-2003) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 3).
  2. "Prediction of the coding sequences of mouse homologues of KIAA gene: IV. The complete nucleotide sequences of 500 mouse KIAA-homologous cDNAs identified by screening of terminal sequences of cDNA clones randomly sampled from size-fractionated libraries."
    Okazaki N., Kikuno R., Ohara R., Inamoto S., Koseki H., Hiraoka S., Saga Y., Seino S., Nishimura M., Kaisho T., Hoshino K., Kitamura H., Nagase T., Ohara O., Koga H.
    DNA Res. 11:205-218(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2).
    Tissue: Pancreatic islet.
  3. "The transcriptional landscape of the mammalian genome."
    Carninci P., Kasukawa T., Katayama S., Gough J., Frith M.C., Maeda N., Oyama R., Ravasi T., Lenhard B., Wells C., Kodzius R., Shimokawa K., Bajic V.B., Brenner S.E., Batalov S., Forrest A.R., Zavolan M., Davis M.J.
    , Wilming L.G., Aidinis V., Allen J.E., Ambesi-Impiombato A., Apweiler R., Aturaliya R.N., Bailey T.L., Bansal M., Baxter L., Beisel K.W., Bersano T., Bono H., Chalk A.M., Chiu K.P., Choudhary V., Christoffels A., Clutterbuck D.R., Crowe M.L., Dalla E., Dalrymple B.P., de Bono B., Della Gatta G., di Bernardo D., Down T., Engstrom P., Fagiolini M., Faulkner G., Fletcher C.F., Fukushima T., Furuno M., Futaki S., Gariboldi M., Georgii-Hemming P., Gingeras T.R., Gojobori T., Green R.E., Gustincich S., Harbers M., Hayashi Y., Hensch T.K., Hirokawa N., Hill D., Huminiecki L., Iacono M., Ikeo K., Iwama A., Ishikawa T., Jakt M., Kanapin A., Katoh M., Kawasawa Y., Kelso J., Kitamura H., Kitano H., Kollias G., Krishnan S.P., Kruger A., Kummerfeld S.K., Kurochkin I.V., Lareau L.F., Lazarevic D., Lipovich L., Liu J., Liuni S., McWilliam S., Madan Babu M., Madera M., Marchionni L., Matsuda H., Matsuzawa S., Miki H., Mignone F., Miyake S., Morris K., Mottagui-Tabar S., Mulder N., Nakano N., Nakauchi H., Ng P., Nilsson R., Nishiguchi S., Nishikawa S., Nori F., Ohara O., Okazaki Y., Orlando V., Pang K.C., Pavan W.J., Pavesi G., Pesole G., Petrovsky N., Piazza S., Reed J., Reid J.F., Ring B.Z., Ringwald M., Rost B., Ruan Y., Salzberg S.L., Sandelin A., Schneider C., Schoenbach C., Sekiguchi K., Semple C.A., Seno S., Sessa L., Sheng Y., Shibata Y., Shimada H., Shimada K., Silva D., Sinclair B., Sperling S., Stupka E., Sugiura K., Sultana R., Takenaka Y., Taki K., Tammoja K., Tan S.L., Tang S., Taylor M.S., Tegner J., Teichmann S.A., Ueda H.R., van Nimwegen E., Verardo R., Wei C.L., Yagi K., Yamanishi H., Zabarovsky E., Zhu S., Zimmer A., Hide W., Bult C., Grimmond S.M., Teasdale R.D., Liu E.T., Brusic V., Quackenbush J., Wahlestedt C., Mattick J.S., Hume D.A., Kai C., Sasaki D., Tomaru Y., Fukuda S., Kanamori-Katayama M., Suzuki M., Aoki J., Arakawa T., Iida J., Imamura K., Itoh M., Kato T., Kawaji H., Kawagashira N., Kawashima T., Kojima M., Kondo S., Konno H., Nakano K., Ninomiya N., Nishio T., Okada M., Plessy C., Shibata K., Shiraki T., Suzuki S., Tagami M., Waki K., Watahiki A., Okamura-Oho Y., Suzuki H., Kawai J., Hayashizaki Y.
    Science 309:1559-1563(2005) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
    Strain: C57BL/6J.
    Tissue: Brain cortex.
  4. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: C57BL/6J.
  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).
    Strain: C57BL/6J.
    Tissue: Brain.
  6. "MyD88-5 links mitochondria, microtubules, and JNK3 in neurons and regulates neuronal survival."
    Kim Y., Zhou P., Qian L., Chuang J.Z., Lee J., Li C., Iadecola C., Nathan C., Ding A.
    J. Exp. Med. 204:2063-2074(2007) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, SUBCELLULAR LOCATION, INTERACTION WITH MAPK10.
  7. "Studies of SARM1 uncover similarities between immune and neuronal responses to danger."
    Dalod M.
    Sci. STKE 2007:PE73-PE73(2007) [PubMed] [Europe PMC] [Abstract]
    Cited for: REVIEW.
  8. "The immune adaptor molecule SARM modulates tumor necrosis factor alpha production and microglia activation in the brainstem and restricts West Nile virus pathogenesis."
    Szretter K.J., Samuel M.A., Gilfillan S., Fuchs A., Colonna M., Diamond M.S.
    J. Virol. 83:9329-9338(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION.
  9. Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-548 AND SER-558, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
    Tissue: Brain.
  10. "Sarm1, a negative regulator of innate immunity, interacts with syndecan-2 and regulates neuronal morphology."
    Chen C.Y., Lin C.W., Chang C.Y., Jiang S.T., Hsueh Y.P.
    J. Cell Biol. 193:769-784(2011) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, IDENTIFICATION BY MASS SPECTROMETRY, INTERACTION WITH SDC2, TISSUE SPECIFICITY.
  11. "Neuroscience. dSarm-ing axon degeneration."
    Yu X.M., Luo L.
    Science 337:418-419(2012) [PubMed] [Europe PMC] [Abstract]
    Cited for: REVIEW.
  12. Cited for: FUNCTION, SUBCELLULAR LOCATION, DISRUPTION PHENOTYPE.

Entry informationi

Entry nameiSARM1_MOUSE
AccessioniPrimary (citable) accession number: Q6PDS3
Secondary accession number(s): Q5SYG5
, Q5SYG6, Q6A054, Q6SZW0, Q8BRI9
Entry historyi
Integrated into UniProtKB/Swiss-Prot: May 10, 2005
Last sequence update: July 5, 2004
Last modified: January 20, 2016
This is version 113 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. MGD cross-references
    Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot
  2. SIMILARITY comments
    Index of protein domains and families

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 one 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.