MSL dosage compensation complex in Drosophila melanogaster

The male-specific lethal (MSL) complex doubles transcription of the single X chromosome in males. It contains five proteins, MSL1, MSL2, MSL3, the acetyltransferase MOF and the RNA helicase MLE, and one of two long noncoding RNAs, roX1 or roX2, which are redundant. MSL2 is made only in males and nucleates assembly; MLE remodels the roX RNAs to incorporate them. The complex binds high-affinity sites on the X and spreads to active genes, where MOF acetylates histone H4 lysine 16 to raise transcription.

MODULE:dmel_msl_dosage_compensation_complexDRAFTCONCRETEProtein Complexmodules/dmel_msl_dosage_compensation_complex.yaml

MSL complexGO:0072487

FB:FBgg0000283

FlyBase gene group MSL: Male specific lethal complex

FlyBase release FB2026_03 groups 7 D. melanogaster genes as male specific lethal complex (MSL); this module models that group.

GO:0072487

MSL complex

GO term grounding the module as MSL complex.

The roX RNAs have no protein product and are grounded to their FlyBase gene ids; their nodes are typed MODULE, because the schema has no RNA or ribonucleoprotein node type and PROTEIN_COMPLEX would misdescribe a single lncRNA. MSL2 ubiquitin ligase activity (toward histone H2B and the complex's own subunits) is recorded with the general ubiquitin protein ligase term. FlyBase groups realized by this module: MSL (FBgg0000283). 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_msl_dosage_compensation_complex.yaml. Genes without a usable UniProtKB entry are grounded to their FlyBase gene ids: lncRNA:roX1, lncRNA:roX2. Member genes with a gene review in this repository: mle, mof, msl-1, msl-2, msl-3.

5Nodes

2Parts

1Variant Sets

2Variants

3Annotons

0Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_msl_dosage_compensation_complex 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

3 gene-function check(s) reflected in core functions · 0 conflict(s) · 0 evidence or coverage gap(s) (3 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.

Annoton	Participant	Function	Assessment
msl_protein_core_complex/msl_2	msl-2 UniProtKB:P50534 Complex Unit	ubiquitin protein ligase activity GO:0061630	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
msl_protein_core_complex/mof	mof UniProtKB:O02193 Complex Unit	histone H4K16 acetyltransferase activity GO:0046972	Core Supported The GO molecular function is reflected in core_functions (exact term or a reviewed subclass).
msl_protein_core_complex/mle	mle UniProtKB:P24785 Complex Unit	RNA helicase activity GO:0003724	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)

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

Gene	Review	Complete	Deep research
mle P24785	✓	77/78	✓
mof O02193	✓	✓	✓
msl-1 P50535	✓	✓	✓
msl-2 P50534	✓	✓	✓
msl-3 P50536	✓	53/55	✓

Tree

MSL complexProtein Complexdmel_msl_dosage_compensation_complex

Parts
1. 1. X-targeting and H4K16 acetylation
2. MSL protein subunitsProtein Complexmsl_protein_core
  
  Annotons
  - MSL protein subunits Protein Complex: MSL protein subunits
3. 2. RNA subunits
4. roX long noncoding RNAsModulerox_rnas
  
  Variants
  1. roX1 or roX2 (One Or More)
    
    roX1 RNAModulerox1
    
    Annotons
    
    lncRNA:roX1 roX1 RNA Gene: lncRNA:roX1
    
    roX2 RNAModulerox2
    
    Annotons
    
    lncRNA:roX2 roX2 RNA Gene: lncRNA:roX2

Details

Context

Drosophila melanogasterNCBITaxon:7227

X chromosomeGO:0000805

MSL complexProtein Complexdmel_msl_dosage_compensation_complex

Male-specific MSL proteins and roX RNAs that acetylate H4K16 on the male X to upregulate its transcription.

MSL complexGO:0072487

Context

Drosophila melanogasterNCBITaxon:7227

X chromosomeGO:0000805

Part 1: X-targeting and H4K16 acetylation

MSL protein subunitsProtein Complexmsl_protein_core

Annotons

MSL protein subunits

msl_protein_core_complex

Participant: Protein Complex: MSL protein subunits

Protein Complex:

MSL protein subunits

Active units:

msl-1

Participant: Gene Product: msl-1

Gene Product:

msl-1UniProtKB:P50535

msl-2

Participant: Gene Product: msl-2

Gene Product:

msl-2UniProtKB:P50534

Function:

ubiquitin protein ligase activityGO:0061630

msl-3

Participant: Gene Product: msl-3

Gene Product:

msl-3UniProtKB:P50536

mof

Participant: Gene Product: mof

Gene Product:

mofUniProtKB:O02193

Function:

histone H4K16 acetyltransferase activityGO:0046972

mle

Participant: Gene Product: mle

Gene Product:

mleUniProtKB:P24785

Function:

RNA helicase activityGO:0003724

Processes

dosage compensation by hyperactivation of X chromosomeGO:0009047

Part 2: RNA subunits

roX long noncoding RNAsModulerox_rnas

Variant set: roX1 or roX2 (One Or More)

roX1 RNAModulerox1

Annotons

lncRNA:roX1 roX1 RNA

rox1_lncrna_rox1

Participant: Gene: lncRNA:roX1

Gene:

lncRNA:roX1FB:FBgn0019661

roX2 RNAModulerox2

Annotons

lncRNA:roX2 roX2 RNA

rox2_lncrna_rox2

Participant: Gene: lncRNA:roX2

Gene:

lncRNA:roX2FB:FBgn0019660