DP00736: Protein argonaute-2FASTA viewXML view

General information
DisProt:DP00736
Name:Protein argonaute-2
Synonym(s):AGO2_HUMAN
Eukaryotic translation initiation factor 2C 2
PAZ Piwi domain protein
Protein slicer
Argonaute2 or Argonaute-2
hAgo2 or Ago2
eIF-2C 2 or eIF2C 2
PPD
First appeared in release:Release 6.01 (10/15/2012)
UniProt:Q9UKV8
UniGene: 
SwissProt: AGO2_HUMAN
TrEMBL:  
NCBI (GI):  
Source organism:Homo sapiens (Human)
Sequence length:859
Percent disordered:33%
Homologues: 


Native sequence

        10         20         30         40         50         60
         |          |          |          |          |          |
MYSGAGPALA PPAPPPPIQG YAFKPPPRPD FGTSGRTIKL QANFFEMDIP KIDIYHYELD - 60
IKPEKCPRRV NREIVEHMVQ HFKTQIFGDR KPVFDGRKNL YTAMPLPIGR DKVELEVTLP - 120
GEGKDRIFKV SIKWVSCVSL QALHDALSGR LPSVPFETIQ ALDVVMRHLP SMRYTPVGRS - 180
FFTASEGCSN PLGGGREVWF GFHQSVRPSL WKMMLNIDVS ATAFYKAQPV IEFVCEVLDF - 240
KSIEEQQKPL TDSQRVKFTK EIKGLKVEIT HCGQMKRKYR VCNVTRRPAS HQTFPLQQES - 300
GQTVECTVAQ YFKDRHKLVL RYPHLPCLQV GQEQKHTYLP LEVCNIVAGQ RCIKKLTDNQ - 360
TSTMIRATAR SAPDRQEEIS KLMRSASFNT DPYVREFGIM VKDEMTDVTG RVLQPPSILY - 420
GGRNKAIATP VQGVWDMRNK QFHTGIEIKV WAIACFAPQR QCTEVHLKSF TEQLRKISRD - 480
AGMPIQGQPC FCKYAQGADS VEPMFRHLKN TYAGLQLVVV ILPGKTPVYA EVKRVGDTVL - 540
GMATQCVQMK NVQRTTPQTL SNLCLKINVK LGGVNNILLP QGRPPVFQQP VIFLGADVTH - 600
PPAGDGKKPS IAAVVGSMDA HPNRYCATVR VQQHRQEIIQ DLAAMVRELL IQFYKSTRFK - 660
PTRIIFYRDG VSEGQFQQVL HHELLAIREA CIKLEKDYQP GITFIVVQKR HHTRLFCTDK - 720
NERVGKSGNI PAGTTVDTKI THPTEFDFYL CSHAGIQGTS RPSHYHVLWD DNRFSSDELQ - 780
ILTYQLCHTY VRCTRSVSIP APAYYAHLVA FRARYHLVDK EHDSAEGSHT SGQSNGRDHQ - 840
ALAKAVQVHQ DTLRTMYFA



Functional narrative    

Function: Required for RNA-mediated gene silencing (RNAi) by the RNA-induced silencing complex (RISC). The 'minimal RISC' appears to include EIF2C2/AGO2 bound to a short guide RNA such as a microRNA (miRNA) or short interfering RNA (siRNA). These guide RNAs direct RISC to complementary mRNAs that are targets for RISC- mediated gene silencing. The precise mechanism of gene silencing depends on the degree of complementarity between the miRNA or siRNA and its target. Binding of RISC to a perfectly complementary mRNA generally results in silencing due to endonucleolytic cleavage of the mRNA specifically by EIF2C2/AGO2. Binding of RISC to a partially complementary mRNA results in silencing through inhibition of translation, and this is independent of endonuclease activity. May inhibit translation initiation by binding to the 7- methylguanosine cap, thereby preventing the recruitment of the translation initiation factor eIF4-E. May also inhibit translation initiation via interaction with EIF6, which itself binds to the 60S ribosomal subunit and prevents its association with the 40S ribosomal subunit. The inhibition of translational initiation leads to the accumulation of the affected mRNA in cytoplasmic processing bodies (P-bodies), where mRNA degradation may subsequently occur. In some cases RISC-mediated translational repression is also observed for miRNAs that perfectly match the 3' untranslated region (3'-UTR). Can also up-regulate the translation of specific mRNAs under certain growth conditions. Binds to the AU element of the 3'-UTR of the TNF (TNF-alpha) mRNA and up-regulates translation under conditions of serum starvation. Also required for transcriptional gene silencing (TGS), in which short RNAs known as antigene RNAs or agRNAs direct the transcriptional repression of complementary promoter regions.
CATALYTIC ACTIVITY: Endonucleolytic cleavage to 5'- phosphomonoester.
ENZYME REGULATION: Inhibited by EDTA. Kinetic parameters: KM=1.1 nM for a synthetic 21-nucleotide single-stranded RNA;
SUBUNIT: Interacts with DICER1 through its Piwi domain and with TARBP2 during assembly of the RNA-induced silencing complex (RISC). Together, DICER1, EIF2C2/AGO2 and TARBP2 constitute the trimeric RISC loading complex (RLC), or micro-RNA (miRNA) loading complex (miRLC). Within the RLC/miRLC, DICER1 and TARBP2 are required to process precursor miRNAs (pre-miRNAs) to mature miRNAs and then load them onto EIF2C2/AGO2. EIF2C2/AGO2 bound to the mature miRNA constitutes the minimal RISC and may subsequently dissociate from DICER1 and TARBP2. Note however that the term RISC has also been used to describe the trimeric RLC/miRLC. The formation of RISC complexes containing siRNAs rather than miRNAs appears to occur independently of DICER1. Interacts with EIF2C1/AGO1. Also interacts with DDB1, DDX5, DDX6, DDX20, DHX30, DHX36, DDX47, DHX9, EIF6, ELAVL, FXR1, GEMIN4, HNRNPF, IGF2BP1, ILF3, IMP8, MATR3, MOV10, PABPC1, PRMT5, P4HA1, P4HB, RBM4, SART3, TNRC6A, TNRC6B, UPF1 and YBX1. Interacts with the P-body components DCP1A and XRN1. Associates with polysomes and messenger ribonucleoproteins (mNRPs). Interacts with RBM4; the interaction is modulated under stress-induced conditions, occurs under both cell proliferation and differentiation conditions and in a RNA- and phosphorylation-independent manner. Interacts with LIMD1, WTIP and AJUBA. Q9UPY3:DICER1; NbExp=6; IntAct=EBI-528269, EBI-395506; O15397:IPO8; NbExp=3; IntAct=EBI-528269, EBI-358808;


Subcellular Location: Cytoplasm, P-body. Nucleus. Note=Translational repression of mRNAs results in their recruitment to P-bodies. Translocation to the nucleus requires IMP8. Event=Alternative splicing; Named isoforms=2; Name=1; IsoId=Q9UKV8-1; Sequence=Displayed; Name=2; IsoId=Q9UKV8-2; Sequence=VSP_037001; Note=No experimental confirmation available;
DOMAIN: The Piwi domain may perform RNA cleavage by a mechanism similar to that of RNase H. However, while RNase H utilizes a triad of Asp-Asp-Glu (DDE) for metal ion coordination, this protein appears to utilize a triad of Asp-Asp-His (DDH).
PTM: Hydroxylated. 4-hydroxylation appears to enhance protein stability but is not required for miRNA-binding or endonuclease activity.
SIMILARITY: Belongs to the argonaute family. Ago subfamily.
SIMILARITY: Contains 1 PAZ domain.
SIMILARITY: Contains 1 Piwi domain. Sequence=AAH07633.1; Type=Erroneous initiation; Sequence=AAL76093.1; Type=Miscellaneous discrepancy; Note=cDNA contains a duplication of an internal sequence at the 5' end; Sequence=BC125214; Type=Frameshift; Positions=450.
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Region 1: 1-31 Region 2: 119-126 Region 3: 136-229 Region 4: 271-276 Region 5: 348-450 Region 6: 602-609 Region 7: 818-847

Map of ordered and disordered regions







Note: 'Mouse' over a region to see the start and stop residues. Click on a region to see detailed information.


Region 1
Type:Disordered
Name:N-terminal region
Location:1 - 31
Length:31
Region sequence:

MYSGAGPALAPPAPPPPIQGYAFKPPPRPDF

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; PEG3350 16 %; isopropanol 12 %; phenol 0.1 M; Tris 0.1 M; ssRNA (~10-20 nt, synthetic construct))

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 16 %; L-tryptophan (saturated); PEG3350 12 %; Tris 0.1 M; ssRNA (~10-20 nt, synthetic construct))

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) found no density at residues M1-A22. They describe M1-F31 as an "eukaryotic-specific insertion." Eukaryotic-specific insertions are as compared to bacterial T. thermophilus Ago2. Human Ago2 has 15 such insertions, eight of which overlap fully or in part with disordered regions.




Region 2
Type:Disordered
Name:disordered loop
Location:119 - 126
Length:8
Region sequence:

LPGEGKDR

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; isopropanol 12 %; PEG3350 16 %; phenol 0.1 M; Tris 0.1 M; ssRNA (~10-20 nt, synthetic construct))

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 12 %; L-tryptophan (saturated); PEG3350 16 %; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) found no density at residues L119-D125. They describe L119-R126 as an "eukaryotic-specific insertion." Eukaryotic-specific insertions are as compared to bacterial T. thermophilus Ago2. Human Ago2 has 15 such insertions, eight of which overlap fully or in part with disordered regions.




Region 3
Type:Disordered - Extended
Name:Loop 1 (L1)
Location:136 - 229
Length:94
Region sequence:

SCVSLQALHDALSGRLPSVPFETIQALDVVMRHLPSMRYTPVGRSFFTASEGCSNPLGGG
REVWFGFHQSVRPSLWKMMLNIDVSATAFYKAQP

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; isopropanol 12 %; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; PEG3350 16 %; phenol 0.1 M; Tris 0.1 M; ssRNA (~10-20 nt, synthetic construct))

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 12 %; L-tryptophan (saturated); PEG3350 16 %; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) describe Region 3 Loop 1 as an extended loop at aa L140-P229. A small region of no density is found at E186-C188. Preceding and partially overlapping Loop 1, there is an "eukaryotic-specific insertion" at aa S136-D145. Eukaryotic-specific insertions are as compared to bacterial T. thermophilus Ago2. Human Ago2 has 15 such insertions, eight of which overlap fully or in part with disordered regions.




Region 4
Type:Disordered
Name:disordered loop
Location:271 - 276
Length:6
Region sequence:

HCGQMK

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; isopropanol 12 %; PEG3350 16 %; phenol 0.1 M; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 12 %; L-tryptophan (saturated); PEG3350 16 %; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) found no density at residues H271-K276.




Region 5
Type:Disordered - Extended
Name:Loop 2 (L2)
Location:348 - 450
Length:103
Region sequence:

AGQRCIKKLTDNQTSTMIRATARSAPDRQEEISKLMRSASFNTDPYVREFGIMVKDEMTD
VTGRVLQPPSILYGGRNKAIATPVQGVWDMRNKQFHTGIEIKV

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; isopropanol 12 %; PEG3350 16 %; phenol 0.1 M; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 12 %; L-tryptophan (saturated); PEG3350 16 %; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) describe Region 5 Loop 2 as an extended loop at aa A348-T445. Three "eukaryotic-specific insertions" are found at aa Q360-T368, T390-G398 and H443-V450. The latter extends 5 residues beyond the end of Loop 2.

Eukaryotic-specific insertion Q360-T368 contains alpha-Helix 7 at D358-T368. According to the authors, alpha-Helix 7, and particularly M364-I365, are instrumental in forming a kink in the guide RNA, stating "[t]he ability of Ago2 to kink guide RNAs may also facilitate release of sliced RNA products by disrupting guide-target pairing in this region."

Eukaryotic-specific insertions are as compared to bacterial T. thermophilus Ago2. Human Ago2 has 15 such insertions, eight of which overlap fully or in part with disordered regions.




Region 6
Type:Disordered
Name:disordered loop
Location:602 - 609
Length:8
Region sequence:

PAGDGKKP

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; isopropanol 12 %; PEG3350 16 %; phenol 0.1 M; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 12 %; L-tryptophan (saturated); PEG3350 16 %; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) found no density at residues P602-G606 and they describe D605-P609 as an "eukaryotic-specific insertion." Eukaryotic-specific insertions are as compared to bacterial T. thermophilus Ago2. Human Ago2 has 15 such insertions, eight of which overlap fully or in part with disordered regions.




Region 7
Type:Disordered
Name:disordered loop
Location:818 - 847
Length:30
Region sequence:

VDKEHDSAEGSHTSGQSNGRDHQALAKAVQ

Modification type: Mutant
PDB: 4EI1:A, 4EI3:A
Structural/functional type: Function arises from the disordered state
Functional classes: Molecular recognition effectors
Functional subclasses: Protein-RNA binding
Detection methods:
  1. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI1; mut S387D) 3 mg/mL; isopropanol 12 %; PEG3350 16 %; phenol 0.1 M; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

  2. X-ray crystallography (293 K; pH: 9; Argonaute-2 (PDB 4EI3; mut S387D) 3 mg/mL; isopropanol 12 %; L-tryptophan (saturated); PEG3350 16 %; ssRNA (~10-20 nt, synthetic construct); Tris 0.1 M)

References:
  1. Schirle NT, MacRae IJ. "The crystal structure of human Argonaute2." Science. 2012; 336(6084): 1037-40. PubMed: 22539551

Comments:
Schirle and MacRae (2012) found no density at residues V818-D838 and they describe E821-Q847 as an "eukaryotic-specific insertion." Eukaryotic-specific insertions are as compared to bacterial T. thermophilus Ago2. Human Ago2 has 15 such insertions, eight of which overlap fully or in part with disordered regions.

Further, the authors state that eukaryotic-specific insertion E821-Q847 may act in concert with alpha-Helix 5 (D252-I262) "to form a clamp around bound guide-target [RNA] duplexes."




Comments


AV sent 10/3/2012 ( PMID 22539551)


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