18 Heterologous Gene Expression in Filamentous Fungi CEES A. M. J. J. VAN DEN HONDEL PETER J. PUNT ROBERT F. ML VAN GORCOM TNO Medical Biology Laboratory Rijswijk, The Netherlands I. Introduction 397 II. Transcription Control Sequences of Fungal Genes 398 A. Isolation of Transcription Control Sequences 398 B. Characterization of the Functions of Transcription Control Sequences 399 C. Transcription Control Sequences in Heterologous Gene Ex- pression 401 III. Expression Systems for Heterologous Gene Expression 401 A. Expression Cassettes Designed for Heterologous Gene Expres- sion 406 B. Amplification of Expression Cassettes 408 C. Strains Constructed for Optimal Expression 410 IV. Overexpression of Heterologous Proteins 412 A. Production of Intracellular Proteins 413 B. Production of Extracellular Proteins 413 C. Evaluation of Overexpression Results 418 V. Future Prospects 421 References 422 MORE GENE MANIPULATIONS IN FUNGI 396 Copyright © 1991 by Academic Press, Inc. All rights of reproduction in any form reserved.