The STRIPAK complex is a conserved multi-protein complex, which is found in animals and in fungi but not in prokaryotes and plants. It is involved in growth and development, regulating signal transduction in cellular pathways, for example hippo and MAPK, and it has a role in human neuronal diseases, cell fusion, and cancer (1, 2). Small coiled-coil (CC) proteins were described in the STRIPAK complex of humans, in the Far complex of S. cerevisiae, in the SIP complex of S. pombe and in the STRIPAK complex of D. melanogaster (dSTRIPAK) (3-8). However, the function of small CC proteins in the STRIPAK complex is poorly investigated. We identified SCI1, a small CC protein belonging to the STRIPAK complex in the filamentous ascomycete S. macrospora. As all other STRIPAK components, SCI1 is required for development, hyphal fusion and vegetative growth.