The role of the Aspergillus niger furin-type protease gene in processing of fungal proproteins and fusion proteins : Evidence for alternative processing of recombinant (fusion-) proteins

• Published in: Journal of biotechnology Vol. 106; no. 1; pp. 23 - 32
• Main Authors: Punt, P.J, Drint-Kuijvenhoven, A, Lokman, B.C, Spencer, J.A, Jeenes, D, Archer, D.A, van den Hondel, C.A.M.J.J
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05-12-2003; Amsterdam Elsevier; New York, NY
• Subjects: aspergillopepsin; Aspergillus niger; Aspergillus niger - genetics; Aspergillus niger - metabolism; Biological and medical sciences; Biotechnology; Endopeptidases - genetics; Endopeptidases - metabolism; endoproteinase; Filamentous fungi; Fundamental and applied biological sciences. Psychology; Fungal Proteins - biosynthesis; Fungal Proteins - genetics; furin; Furin - genetics; Furin - metabolism; Fusion-proteins; Gene Expression Regulation, Enzymologic - physiology; Gene Expression Regulation, Fungal - physiology; kexB gene; Protease; Protein processing; Protein Processing, Post-Translational - physiology; Protein secretion; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - genetics; Secretion carrier; Transcriptional Activation - physiology; Protein secretion; Protein processing; Fusion-proteins; Secretion carrier; Protease; Filamentous fungi; Molecular processing; Serine endopeptidases; Enzyme; Secretion; Fungi; Peptidases; Gene; Aspergillus niger; Hydrolases; Furin; Fungi Imperfecti; Recombinant protein; Fusion protein; Thallophyta
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2003.09.005

We have characterized growth and protein processing characteristics of
Aspergillus niger strains carrying a disrupted allele of the previously cloned and characterized
kexB gene [Appl. Environ. Microbiol. 66 (2000) 363] encoding a furin-type endoprotease. Deletion of the single-copy gene confirms it to be non-essential but disruptant strains exhibit a morphologically distinct phenotype characterized by hyperbranching. Processing of homologous pro-proteins and fusion proteins comprised of a heterologous protein fused down-stream of glucoamylase and separated at the fusion junction by an endoproteolytic cleavage site was compared in wildtype and mutant strains of
A. niger. We show that maturation of the native glucoamylase requires KexB, whereas maturation of aspergillopepsin does not. The processing of fusion proteins carrying Lys–Arg requires KexB, although alternative endoproteases are capable of cleaving protein fusions at sites adjacent to Lys–Arg.