Component of the VEL2-VOS1 heterodimeric complex that plays a dual role in activating genes associated with spore maturation and repressing certain development-associated genes (By similarity). The complex binds DNA through the DNA-binding domain of VOS1 that recognizes an 11-nucleotide consensus sequence 5'-CTGGCCGCGGC-3' consisting of two motifs in the promoters of key developmental regulatory genes (By similarity). Required for normal pseudothecium development and regulates asexual spore compartmentalization, pigmentation and germination (PubMed:25080135). Forms a heterodimeric complex with VEL2; the formation of the VEL2-VOS1 complex is light-dependent (By similarity). Expression is negatively regulated by VEL1 (PubMed:25080135). The N-terminal velvet domain contains a NF-kappa-B-like fold and is involved in DNA-binding (By similarity). Produces only albino pseudothecia (PubMed:25080135). Reduces tolerance to oxidative and thermal stresses (PubMed:25080135). Belongs to the velvet family. VosA subfamily.