Component of the velB-VosA heterodimeric complex that plays a dual role in activating genes associated with spore maturation and repressing certain development-associated genes (PubMed:17912349, PubMed:21152013, PubMed:23049895, PubMed:24391470). Controls primarily the late process of sporulation including trehalose biogenesis (PubMed:17912349). The complex binds DNA through the DNA-binding domain of vosA that recognizes an 11-nucleotide consensus sequence 5'-CTGGCCGCGGC-3' consisting of two motifs in the promoters of key developmental regulatory genes (PubMed:24391470). The vosA-velB complex binds to the beta-glucan synthase fksA gene promoter in asexual spores for repression (PubMed:25960370). Forms a heterodimeric complex with VelB; the formation of the velB-vosA complex is light-dependent (PubMed:21152013, PubMed:23049895). Interacts also with velC (PubMed:24587098). Localizes in the nucleus of mature conidia (PubMed:17912349). Expression is induced in conidia, ascospores and during the late phase of conidiation when conidia differentiate and become mature (PubMed:17912349). During vegetative growth, expression quickly drops and continues to be undetectable (or low) until 24 hours post induction of conidiation (PubMed:17912349). Expression is positively regulated by abaA (PubMed:23049895). Expression is under the regulation of the flbE transcription factor (PubMed:20817115). Expression is also under the regulation of the flbC transcription factor (PubMed:20624219). The N-terminal velvet domain contains a NF-kappa-B-like fold and is involved in DNA-binding (PubMed:24391470). Results in the lack of trehalose in spores, a rapid loss of the cytoplasm, organelles and viability of spores, and a dramatic reduction in tolerance of conidia to heat and oxidative stress (PubMed:17912349). Down-regulates genes associated with spore maturation and up-regulates certain development-associated genes (PubMed:24391470). Results in elevated accumulation of beta-glucan in asexual spores (PubMed:25960370). Belongs to the velvet family. VosA subfamily.