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.
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.
Punt
P J
PJ
TNO Nutrition and Food Research, Department of Applied Microbiology and Gene Technology, 3700 AJ Zeist, The Netherlands. p.punt@voeding.tno.nl
Drint-Kuijvenhoven
A
A
Lokman
B C
BC
Spencer
J A
JA
Jeenes
D
D
Archer
D A
DA
van den Hondel
C A M J J
CA
D001234:Aspergillus niger / Q000235:genetics* / Q000378:metabolism*; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics*; D045683:Furin / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000235:genetics*; D015533:Transcriptional Activation / Q000502:physiology
D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D010450:Endopeptidases; D045683:Furin