brlA (Aspergillus nidulans) — curation notes

UniProt: P10069 (BRLA_EMENI). C2H2 zinc-finger transcription factor; master
regulator of conidiophore development ("bristle"). Part of the
conidiation_regulatory_cascade module.

Core biology (with provenance)

• Master switch, necessary and sufficient. brlA mediates the developmental
  switch from indeterminate apical hyphal growth to the budding growth pattern of
  the conidiophore; misscheduled (forced) expression in vegetative cells activates
  developmentally regulated genes and drives conidiophore/spore formation.
  PMID:3293800;
  PMID:3293800.
• C2H2 zinc-finger TF. 432-aa polypeptide with two directly repeated
  TFIIIA-type Zn(II) coordination motifs.
  PMID:3293800.
• DNA-binding transcriptional regulator (direct). BrlA binds specific DNA
  response elements (BREs); expressed in yeast it activates a BRE-driven reporter,
  demonstrating sequence-specific transcriptional activation.
  PMID:8417986;
  PMID:8417986.
• Top of the brlA→abaA→wetA dependent pathway. The three genes form a
  dependent pathway regulating asexual reproductive development; brlA expression
  activates abaA and wetA and leads to cessation of vegetative growth and spore
  formation.
  PMID:2655931;
  PMID:2655931.
• Two overlapping transcription units brlAα / brlAβ, individually required for
  conidiophore development.
  PMID:8508769.
• Induced by the FluG/Flb upstream activators. Recessive mutations in
  fluG/flbA–E reduce brlA expression (fluffy phenotype), placing brlA downstream
  of the developmental-competence machinery.
  PMID:9339347.

Secondary / non-core roles

• Secondary metabolism link. brlA activity also affects sterigmatocystin (ST)
  biosynthesis and secondary-metabolite regulation (dominant mutations affect both
  sporulation and ST). Real but non-core relative to the conidiation master-switch
  function. PMID:9339347.
• Autolysis. Asexual-sporulation signalling (including brlA) modulates
  autolysis via chitinase ChiB. Downstream/non-core. PMID:19486415.
• Starvation. brlA expression is modulated by starvation stress (IEP) — a
  regulatory input to brlA, not brlA acting in the starvation response.
  PMID:7894714.

Annotation-review judgments

• Core MF: DNA-binding transcription factor activity (GO:0003700 IDA; GO:0000981
  IBA) — ACCEPT.
• Core BP: positive regulation of conidium formation (GO:0075307), conidium
  formation (GO:0048315), conidiophore/sporocarp development (GO:0000905),
  regulation of transcription by RNA Pol II (GO:0006357) — ACCEPT.
• Non-core (real): ST/secondary-metabolite regulation (GO:0010913, GO:1900376),
  autolysis (GO:0001896), starvation response IEP (GO:0042594) — KEEP_AS_NON_CORE.
• Over-annotation: sterigmatocystin biosynthetic process (GO:0045461) — brlA is
  a regulator, not part of ST biosynthesis; the regulation term GO:0010913 already
  captures the real relationship. Also the IBA response to starvation
  (GO:0042594, involved_in) is a phylogenetic over-propagation from SGD paralogs.