Identification of protein complexes from filamentous fungi with tandem affinity purification.

Fungal molecular biology has benefited from the enormous advances in understanding protein-protein interactions in prokaryotic or eukaryotic organisms of the past decade. Tandem affinity purification (TAP) allows the enrichment of native protein complexes from cell extracts under mild conditions. We codon-optimized tags and established TAP, previously not applicable to filamentous fungi, for the model organism Aspergillus nidulans. We could identify by this method the trimeric Velvet complex VelB/VeA/LaeA or the eight subunit COP9 signalosome. Here, we describe an optimized protocol for A. nidulans which can also be adapted to other filamentous fungi.