Protein phosphatase 2A holoenzymes in Drosophila melanogaster

Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase formed by a core dimer of a scaffold (A) subunit and a catalytic (C) subunit, joined by one of several regulatory B subunits that select substrates and subcellular location. In Drosophila the catalytic subunit is Microtubule star (Mts) and the scaffold is Pp2A-29B. The B55-family subunit Twins (Tws) directs PP2A to mitotic substrates and regulates mitotic exit, while the B56 subunits Widerborst (Wdb) and Well rounded (Wrd) act in planar cell polarity, Hedgehog and Wingless signaling, insulin signaling and synapse development.

MODULE:dmel_pp2a_holoenzymesDRAFTCONCRETEProtein Complexmodules/dmel_pp2a_holoenzymes.yaml
protein phosphatase type 2A complexGO:0000159
FB:FBgg0000909
FlyBase gene group PP2A: Protein phosophatase 2a complexes
FlyBase release FB2026_03 groups 5 D. melanogaster genes as protein phosophatase 2a complexes (PP2A); this module models that group.
GO:0000159
protein phosphatase type 2A complex
GO term grounding the module as protein phosphatase type 2A complex.

FlyBase defines three holoenzymes (WRD-PP2A, TWS-PP2A, WDB-PP2A) that share the A and C subunits; they are modelled as one core part plus an EXACTLY_ONE B-subunit choice. The striatin-containing PP2A of STRIPAK is a separate module (dmel_stripak_complex). The B'' subunit and PP2A inhibitors are not in the FlyBase group and are not modelled. FlyBase groups realized by this module: PP2A (FBgg0000909). Subgroups folded into it: WRD-PP2A, TWS-PP2A, WDB-PP2A. 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_pp2a_holoenzymes.yaml. Member genes with a gene review in this repository: mts, Pp2A-29B, tws, wdb, wrd.

6Nodes
2Parts
1Variant Sets
3Variants
4Annotons
1Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_pp2a_holoenzymes 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

4 gene-function check(s) reflected in core functions · 0 conflict(s) · 0 evidence or coverage gap(s) (4 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
pp2a_core_enzyme_complex/mts mts
UniProtKB:P23696
Complex Unit 		protein serine/threonine phosphatase activity
GO:0004722 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
tws_b55_tws tws
UniProtKB:P36872
Gene 		protein phosphatase regulator activity
GO:0019888 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
wdb_b56_wdb wdb
UniProtKB:A0A6F7R657
Gene 		protein phosphatase regulator activity
GO:0019888 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
wrd_b56_wrd wrd
UniProtKB:Q8IN89
Gene 		protein phosphatase regulator activity
GO:0019888 		Core Supported
The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).

Gene-review completeness (5/5 grounded genes reviewed)

2 complete review(s) · 5 with deep research · 0 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
mts P23696 ✓ 88/91 ✓
Pp2A-29B P36179 ✓ 67/69 ✓
tws P36872 ✓ 50/51 ✓
wdb A0A6F7R657 ✓ ✓ ✓
wrd Q8IN89 ✓ ✓ ✓

Details

Context
Drosophila melanogasterNCBITaxon:7227
PP2A holoenzymesProtein Complexdmel_pp2a_holoenzymes

Mts-Pp2A-29B core with alternative Tws, Wdb or Wrd regulatory subunits.

protein phosphatase type 2A complexGO:0000159
Context
Drosophila melanogasterNCBITaxon:7227

Connections

pp2a_regulatory_subunit -> pp2a_core_enzyme Positively Regulates
The B subunit targets the core enzyme to specific substrates and sites.
Part 1: catalytic and scaffold subunits
PP2A core enzymeProtein Complexpp2a_core_enzyme

Annotons

PP2A A-C core dimer
pp2a_core_enzyme_complex
Participant: Protein Complex: PP2A A-C core dimer
Protein Complex:
PP2A A-C core dimer
Active units:
mts
Participant: Gene Product: mts
Gene Product:
mtsUniProtKB:P23696
Function:
protein serine/threonine phosphatase activityGO:0004722
Pp2A-29B
Participant: Gene Product: Pp2A-29B
Gene Product:
Pp2A-29BUniProtKB:P36179
Part 2: substrate-targeting subunit
PP2A regulatory B subunitProtein Complexpp2a_regulatory_subunit
Variant set: B55 or B56 regulatory subunit (Exactly One)
Twins (B55)Protein Complextws_b55

Annotons

tws Twins (B55)
tws_b55_tws
Participant: Gene Product: tws
Gene Product:
twsUniProtKB:P36872

Function

protein phosphatase regulator activityGO:0019888
Widerborst (B56)Protein Complexwdb_b56

Annotons

wdb Widerborst (B56)
wdb_b56_wdb
Participant: Gene Product: wdb
Gene Product:
wdbUniProtKB:A0A6F7R657

Function

protein phosphatase regulator activityGO:0019888
Well rounded (B56)Protein Complexwrd_b56

Annotons

wrd Well rounded (B56)
wrd_b56_wrd
Participant: Gene Product: wrd
Gene Product:
wrdUniProtKB:Q8IN89

Function

protein phosphatase regulator activityGO:0019888