Polycomb group repressive complexes in Drosophila melanogaster

Polycomb group (PcG) proteins maintain the repressed state of developmental regulators such as the Hox genes through cell divisions. They act through several distinct complexes recruited to Polycomb response elements (PREs). PRC2 trimethylates histone H3 lysine 27 through the E(z) methyltransferase. PRC1 binds H3K27me3 through the Polycomb chromodomain and compacts chromatin. dRAF and the variant PRC1-like complexes monoubiquitylate histone H2A lysine 118 through the Sce (dRing) E3 ligase. PhoRC, built around the sequence-specific DNA-binding protein Pho (or its paralog Phol) and Sfmbt, helps target PcG complexes to PREs. PR-DUB, formed by Calypso and Asx, removes H2A ubiquitin.

MODULE:dmel_polycomb_group_complexesDRAFTCONCRETEProtein Complexmodules/dmel_polycomb_group_complexes.yaml
PcG protein complexGO:0031519
FB:FBgg0000273
FlyBase gene group PRC1: Polycomb repressive complex 1, psc variant
FlyBase release FB2026_03 groups 5 D. melanogaster genes as polycomb repressive complex 1, psc variant (PRC1); this module models that group.
FB:FBgg0000276
FlyBase gene group PR-DUB: Polycomb repressive deubiquitinase complex
FlyBase release FB2026_03 groups 2 D. melanogaster genes as polycomb repressive deubiquitinase complex (PR-DUB); this module models that group.
FB:FBgg0000280
FlyBase gene group PRC2: Polycomb repressive complex 2, pcl variant
FlyBase release FB2026_03 groups 5 D. melanogaster genes as polycomb repressive complex 2, pcl variant (PRC2); this module models that group.
FB:FBgg0000289
FlyBase gene group PHORC: Pho repressive complex - pho variant
FlyBase release FB2026_03 groups 2 D. melanogaster genes as pho repressive complex - pho variant (PHORC); this module models that group.
FB:FBgg0000298
FlyBase gene group DRAF: Dring-associated factors complex
FlyBase release FB2026_03 groups 3 D. melanogaster genes as dring-associated factors complex (DRAF); this module models that group.
FB:FBgg0000304
FlyBase gene group PCG-DNA: Polycomb group recruiters/dna-binding proteins
FlyBase release FB2026_03 groups 7 D. melanogaster genes as polycomb group recruiters/dna-binding proteins (PCG-DNA); this module models that group.
FB:FBgg0000309
FlyBase gene group PCG-C: Polycomb group ring finger complexes
FlyBase release FB2026_03 groups 19 D. melanogaster genes as polycomb group ring finger complexes (PCG-C); this module models that group.
FB:FBgg0001835
FlyBase gene group PHORC-L: Pho repressive complex - phol variant
FlyBase release FB2026_03 groups 2 D. melanogaster genes as pho repressive complex - phol variant (PHORC-L); this module models that group.
FB:FBgg0001860
FlyBase gene group PRC1-VAR: Polycomb repressive complex 1, su(z)2 variant
FlyBase release FB2026_03 groups 5 D. melanogaster genes as polycomb repressive complex 1, su(z)2 variant (PRC1-VAR); this module models that group.
FB:FBgg0001861
FlyBase gene group PRC2-JJ: Polycomb repressive complex 2, jarid2-jing variant
FlyBase release FB2026_03 groups 6 D. melanogaster genes as polycomb repressive complex 2, jarid2-jing variant (PRC2-JJ); this module models that group.
FB:FBgg0002236
FlyBase gene group VPRC1-1: Bcorl-siesta-ring1 complex
FlyBase release FB2026_03 groups 7 D. melanogaster genes as bcorl-siesta-ring1 complex (VPRC1-1); this module models that group.
FB:FBgg0002237
FlyBase gene group VPRC1-3-5: Tay-siesta-ring1 complex
FlyBase release FB2026_03 groups 5 D. melanogaster genes as tay-siesta-ring1 complex (VPRC1-3-5); this module models that group.
GO:0031519
PcG protein complex
GO term grounding the module as PcG protein complex.

Catalytic subunits carry the complexes' enzymatic activities, each with GOA support for the fly protein: E(z) histone H3K27 methyltransferase activity in both PRC2 variants (GO:0046976; IDA, IMP, IBA), Sce (dRing) ubiquitin protein ligase activity in every Sce-containing PRC1 and variant PRC1 complex (GO:0061630; IMP, IBA), Kdm2 histone H3K36 demethylase activity in the Kdm2-containing complexes (GO:0051864; IMP, IBA), and Calypso cysteine-type deubiquitinase activity in PR-DUB (GO:0004843; IDA, EXP). Reader and DNA-binding subunits (Pc, Pcl, Sfmbt, Pho, Phol) are not given binding terms as their annoton function. FlyBase groups realized by this module: PRC1 (FBgg0000273), PR-DUB (FBgg0000276), PRC2 (FBgg0000280), PHORC (FBgg0000289), DRAF (FBgg0000298), PCG-DNA (FBgg0000304), PCG-C (FBgg0000309), PHORC-L (FBgg0001835), PRC1-VAR (FBgg0001860), PRC2-JJ (FBgg0001861), VPRC1-1 (FBgg0002236), VPRC1-3-5 (FBgg0002237). Participants were generated from the FlyBase gene-group membership and mapped to UniProtKB by projects/FLYBASE_GENE_GROUPS/generate_modules.py from module_specs/dmel_polycomb_group_complexes.yaml. Member genes with a gene review in this repository: Caf1-55, SkpA.

16Nodes
6Parts
4Variant Sets
9Variants
17Annotons
0Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_polycomb_group_complexes deep-research report alongside the module YAML.

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Function consistency and core coverage

0 gene-function check(s) reflected in core functions · 0 conflict(s) · 10 evidence or coverage gap(s) (10 comparison(s))

Retained noncore functions are reported separately; they do not require promotion to core functions. Support from representative genes does not establish conservation across the whole family. Missing reviews or identifiers leave a claim unverified.

AnnotonParticipantFunctionAssessment
prc2_pcl_complex/e_z E(z)
UniProtKB:P42124
Complex Unit 		histone H3K27 methyltransferase activity
GO:0046976 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
prc2_jarid2_jing_complex/e_z E(z)
UniProtKB:P42124
Complex Unit 		histone H3K27 methyltransferase activity
GO:0046976 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
prc1_psc_complex/sce Sce
UniProtKB:Q9VB08
Complex Unit 		ubiquitin protein ligase activity
GO:0061630 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
prc1_suz2_complex/sce Sce
UniProtKB:Q9VB08
Complex Unit 		ubiquitin protein ligase activity
GO:0061630 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
draf_complex/kdm2 Kdm2
UniProtKB:Q9VHH9
Complex Unit 		histone H3K36 demethylase activity
GO:0051864 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
draf_complex/sce Sce
UniProtKB:Q9VB08
Complex Unit 		ubiquitin protein ligase activity
GO:0061630 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bcorl_siesta_ring1_complex/kdm2 Kdm2
UniProtKB:Q9VHH9
Complex Unit 		histone H3K36 demethylase activity
GO:0051864 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
bcorl_siesta_ring1_complex/sce Sce
UniProtKB:Q9VB08
Complex Unit 		ubiquitin protein ligase activity
GO:0061630 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
tay_siesta_ring1_complex/sce Sce
UniProtKB:Q9VB08
Complex Unit 		ubiquitin protein ligase activity
GO:0061630 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
pr_dub_complex/caly caly
UniProtKB:Q7K5N4
Complex Unit 		cysteine-type deubiquitinase activity
GO:0004843 		Review Missing
No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.

Gene-review completeness (2/31 grounded genes reviewed)

1 complete review(s) · 2 with deep research · 29 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
psq A0A6M3Q7H0 ✗ — —
Caf1-55 Q24572 ✓ 90/91 ✓
CkIIbeta P08182 ✗ — —
z P09956 ✗ — —
grh P13002 ✗ — —
Su(z)2 P25172 ✗ — —
Pc P26017 ✗ — —
Psc P35820 ✗ — —
ph-p P39769 ✗ — —
E(z) P42124 ✗ — —
Trl Q08605 ✗ — —
esc Q24338 ✗ — —
Pcl Q24459 ✗ — —
Dsp1 Q24537 ✗ — —
caly Q7K5N4 ✗ — —
jing Q7KHG2 ✗ — —
CG14073 Q8IQT4 ✗ — —
pho Q8ST83 ✗ — —
Su(z)12 Q9NJG9 ✗ — —
Asx Q9V727 ✗ — —
Sce Q9VB08 ✗ — —
Kdm2 Q9VHH9 ✗ — —
CG8677 Q9VID9 ✗ — —
Sfmbt Q9VK33 ✗ — —
phol Q9VSZ3 ✗ — —
Jarid2 Q9VT00 ✗ — —
sist Q9VV77 ✗ — —
tay Q9VXM5 ✗ — —
RYBP Q9W215 ✗ — —
ph-d Q9W523 ✗ — —
SkpA O77430 ✓ ✓ ✓

Details

Context
Drosophila melanogasterNCBITaxon:7227
chromatinGO:0000785
Polycomb group complexesProtein Complexdmel_polycomb_group_complexes

PcG complexes (PRC1, PRC2, PhoRC, PR-DUB, dRAF and variant PRC1) that establish and maintain Polycomb silencing at PREs.

PcG protein complexGO:0031519
Context
Drosophila melanogasterNCBITaxon:7227
chromatinGO:0000785
Part 1: H3K27 methyltransferase complex
Polycomb repressive complex 2Protein Complexprc2

E(z)-containing complex that trimethylates H3K27. FlyBase distinguishes a Pcl-containing variant and a Jarid2-Jing variant.

ESC/E(Z) complexGO:0035098
Variant set: PRC2 accessory-subunit variants (One Or More)
PRC2 Pcl variantProtein Complexprc2_pcl

Annotons

PRC2 Pcl variant
prc2_pcl_complex
Participant: Protein Complex: PRC2 Pcl variant
Protein Complex:
PRC2 Pcl variantGO:0035098
Active units:
Caf1-55
Participant: Gene Product: Caf1-55
Gene Product:
Caf1-55UniProtKB:Q24572
E(z)
Participant: Gene Product: E(z)
Gene Product:
E(z)UniProtKB:P42124
Function:
histone H3K27 methyltransferase activityGO:0046976
Pcl
Participant: Gene Product: Pcl
Gene Product:
PclUniProtKB:Q24459
Su(z)12
Participant: Gene Product: Su(z)12
Gene Product:
Su(z)12UniProtKB:Q9NJG9
esc
Participant: Gene Product: esc
Gene Product:
escUniProtKB:Q24338
PRC2 Jarid2-Jing variantProtein Complexprc2_jarid2_jing

Annotons

PRC2 Jarid2-Jing variant
prc2_jarid2_jing_complex
Participant: Protein Complex: PRC2 Jarid2-Jing variant
Protein Complex:
PRC2 Jarid2-Jing variantGO:0035098
Active units:
Caf1-55
Participant: Gene Product: Caf1-55
Gene Product:
Caf1-55UniProtKB:Q24572
E(z)
Participant: Gene Product: E(z)
Gene Product:
E(z)UniProtKB:P42124
Function:
histone H3K27 methyltransferase activityGO:0046976
Jarid2
Participant: Gene Product: Jarid2
Gene Product:
Jarid2UniProtKB:Q9VT00
Su(z)12
Participant: Gene Product: Su(z)12
Gene Product:
Su(z)12UniProtKB:Q9NJG9
esc
Participant: Gene Product: esc
Gene Product:
escUniProtKB:Q24338
jing
Participant: Gene Product: jing
Gene Product:
jingUniProtKB:Q7KHG2
Part 2: H3K27me3 reader and chromatin compaction complex
Polycomb repressive complex 1Protein Complexprc1
Variant set: PRC1 Psc or Su(z)2 variants (One Or More)
PRC1 Psc variantProtein Complexprc1_psc

Annotons

PRC1 Psc variant
prc1_psc_complex
Participant: Protein Complex: PRC1 Psc variant
Protein Complex:
PRC1 Psc variantGO:0035102
Active units:
Pc
Participant: Gene Product: Pc
Gene Product:
PcUniProtKB:P26017
Psc
Participant: Gene Product: Psc
Gene Product:
PscUniProtKB:P35820
Sce
Participant: Gene Product: Sce
Gene Product:
SceUniProtKB:Q9VB08
Function:
ubiquitin protein ligase activityGO:0061630
ph-d
Participant: Gene Product: ph-d
Gene Product:
ph-dUniProtKB:Q9W523
ph-p
Participant: Gene Product: ph-p
Gene Product:
ph-pUniProtKB:P39769
PRC1 Su(z)2 variantProtein Complexprc1_suz2

Annotons

PRC1 Su(z)2 variant
prc1_suz2_complex
Participant: Protein Complex: PRC1 Su(z)2 variant
Protein Complex:
PRC1 Su(z)2 variantGO:0035102
Active units:
Pc
Participant: Gene Product: Pc
Gene Product:
PcUniProtKB:P26017
Sce
Participant: Gene Product: Sce
Gene Product:
SceUniProtKB:Q9VB08
Function:
ubiquitin protein ligase activityGO:0061630
Su(z)2
Participant: Gene Product: Su(z)2
Gene Product:
Su(z)2UniProtKB:P25172
ph-d
Participant: Gene Product: ph-d
Gene Product:
ph-dUniProtKB:Q9W523
ph-p
Participant: Gene Product: ph-p
Gene Product:
ph-pUniProtKB:P39769
Part 3: H2AK118 monoubiquitylation
H2A ubiquitylating variant PRC1 complexesProtein Complexh2a_ubiquitylation_complexes
Variant set: dRing-containing H2A ubiquitin ligase complexes (One Or More)
dRING-associated factors complexProtein Complexdraf

Annotons

dRING-associated factors complex
draf_complex
Participant: Protein Complex: dRING-associated factors complex
Protein Complex:
dRING-associated factors complex
Active units:
Kdm2
Participant: Gene Product: Kdm2
Gene Product:
Kdm2UniProtKB:Q9VHH9
Function:
histone H3K36 demethylase activityGO:0051864
Psc
Participant: Gene Product: Psc
Gene Product:
PscUniProtKB:P35820
Sce
Participant: Gene Product: Sce
Gene Product:
SceUniProtKB:Q9VB08
Function:
ubiquitin protein ligase activityGO:0061630
BCORL-Siesta-RING1 complexProtein Complexbcorl_siesta_ring1

Annotons

BCORL-Siesta-RING1 complex
bcorl_siesta_ring1_complex
Participant: Protein Complex: BCORL-Siesta-RING1 complex
Protein Complex:
BCORL-Siesta-RING1 complex
Active units:
CG14073
Participant: Gene Product: CG14073
Gene Product:
CG14073UniProtKB:Q8IQT4
CG8677
Participant: Gene Product: CG8677
Gene Product:
CG8677UniProtKB:Q9VID9
Kdm2
Participant: Gene Product: Kdm2
Gene Product:
Kdm2UniProtKB:Q9VHH9
Function:
histone H3K36 demethylase activityGO:0051864
RYBP
Participant: Gene Product: RYBP
Gene Product:
RYBPUniProtKB:Q9W215
Sce
Participant: Gene Product: Sce
Gene Product:
SceUniProtKB:Q9VB08
Function:
ubiquitin protein ligase activityGO:0061630
SkpA
Participant: Gene Product: SkpA
Gene Product:
SkpAUniProtKB:O77430
sist
Participant: Gene Product: sist
Gene Product:
sistUniProtKB:Q9VV77
Tay-Siesta-RING1 complexProtein Complextay_siesta_ring1

Annotons

Tay-Siesta-RING1 complex
tay_siesta_ring1_complex
Participant: Protein Complex: Tay-Siesta-RING1 complex
Protein Complex:
Tay-Siesta-RING1 complex
Active units:
CkIIbeta
Participant: Gene Product: CkIIbeta
Gene Product:
CkIIbetaUniProtKB:P08182
RYBP
Participant: Gene Product: RYBP
Gene Product:
RYBPUniProtKB:Q9W215
Sce
Participant: Gene Product: Sce
Gene Product:
SceUniProtKB:Q9VB08
Function:
ubiquitin protein ligase activityGO:0061630
sist
Participant: Gene Product: sist
Gene Product:
sistUniProtKB:Q9VV77
tay
Participant: Gene Product: tay
Gene Product:
tayUniProtKB:Q9VXM5
Part 4: PRE targeting
Pho repressive complexProtein Complexphorc
Variant set: Pho or Phol PhoRC (One Or More)
PhoRC Pho variantProtein Complexphorc_pho

Annotons

PhoRC Pho variant
phorc_pho_complex
Participant: Protein Complex: PhoRC Pho variant
Protein Complex:
PhoRC Pho variant
Active units:
Sfmbt
Participant: Gene Product: Sfmbt
Gene Product:
SfmbtUniProtKB:Q9VK33
pho
Participant: Gene Product: pho
Gene Product:
phoUniProtKB:Q8ST83
PhoRC Phol variantProtein Complexphorc_phol

Annotons

PhoRC Phol variant
phorc_phol_complex
Participant: Protein Complex: PhoRC Phol variant
Protein Complex:
PhoRC Phol variant
Active units:
Sfmbt
Participant: Gene Product: Sfmbt
Gene Product:
SfmbtUniProtKB:Q9VK33
phol
Participant: Gene Product: phol
Gene Product:
pholUniProtKB:Q9VSZ3
Part 5: H2A deubiquitylation
Polycomb repressive deubiquitinaseProtein Complexpr_dub

Annotons

Polycomb repressive deubiquitinase
pr_dub_complex
Participant: Protein Complex: Polycomb repressive deubiquitinase
Protein Complex:
Polycomb repressive deubiquitinaseGO:0035517
Active units:
Asx
Participant: Gene Product: Asx
Gene Product:
AsxUniProtKB:Q9V727
caly
Participant: Gene Product: caly
Gene Product:
calyUniProtKB:Q7K5N4
Function:
cysteine-type deubiquitinase activityGO:0004843
Part 6: PRE-binding recruiters
Polycomb group recruiters and DNA-binding proteinsProtein Complexpcg_recruiters

Sequence-specific DNA-binding proteins that FlyBase groups as PcG recruiters.

Annotons

Dsp1 Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_dsp1
Participant: Gene Product: Dsp1
Gene Product:
Dsp1UniProtKB:Q24537
Trl Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_trl
Participant: Gene Product: Trl
Gene Product:
TrlUniProtKB:Q08605
grh Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_grh
Participant: Gene Product: grh
Gene Product:
grhUniProtKB:P13002
pho Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_pho
Participant: Gene Product: pho
Gene Product:
phoUniProtKB:Q8ST83
phol Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_phol
Participant: Gene Product: phol
Gene Product:
pholUniProtKB:Q9VSZ3
psq Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_psq
Participant: Gene Product: psq
Gene Product:
psqUniProtKB:A0A6M3Q7H0
z Polycomb group recruiters and DNA-binding proteins
pcg_recruiters_z
Participant: Gene Product: z
Gene Product:
zUniProtKB:P09956