title: Inactivation of the 20S proteasome in Streptomyces lividans and its influence on the production of heterologous proteins.
abstract: Proteasomes are self-compartmentalizing proteases first discovered in eukaryotes but also occurring in archaea and in bacteria belonging to the order Actinomycetales. In bacteria, proteasomes have so far no known function. In order to evaluate the influence of the 20S proteasome on the production of heterologous proteins by Streptomyces lividans TK24, the production of a number of heterologous proteins, including soluble human tumour necrosis factor receptor II (shuTNFRII) and salmon calcitonin (sCT), was compared with the wild-type TK24, a proteasome-deficient mutant designated PRO41 and a strain complemented for the disrupted proteasome genes (strain PRO41R). S. lividans cells lacking intact proteasome genes are phenotypically indistinguishable from the wild-type or the complemented strain containing functional proteasomes. Using the expression and secretion signals of the subtilisin inhibitor of Streptomyces venezuelae CBS762.70 (Vsi) for shuTNFRII and those of tyrosinase of Streptomyces antibioticus (MelC1) for the production of sCT, both proteins were secreted in significantly higher amounts in the strain PRO41 than in the wild-type S. lividans TK24 or the complemented strain PRO41R. However, the secretion of other heterologous proteins such as shuTNFRI was not enhanced in the proteasome-deficient strain. This suggests that S. lividans TK24 can degrade some heterologous proteins in a proteasome-dependent fashion. The proteasome-deficient strain may therefore be useful for the efficient production of these heterologous proteins.
authors.affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical University, No. 1 Tiantanxili, Beijing 100050, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Hong
authors.affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical University, No. 1 Tiantanxili, Beijing 100050, China.
authors.forename: Lifei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Laboratory of Bacteriology, Rega Institute, Katholieke Universiteit Leuven, Minderbroedersstraat 10, 3000 Leuven, Belgium.
authors.forename: Elke
authors.initials: E
authors.lastname: Lammertyn
authors.affiliation: Laboratory of Bacteriology, Rega Institute, Katholieke Universiteit Leuven, Minderbroedersstraat 10, 3000 Leuven, Belgium.
authors.forename: Nick
authors.initials: N
authors.lastname: Geukens
authors.affiliation: Laboratory of Bacteriology, Rega Institute, Katholieke Universiteit Leuven, Minderbroedersstraat 10, 3000 Leuven, Belgium.
authors.forename: Lieve
authors.initials: L
authors.lastname: Van Mellaert
authors.affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical University, No. 1 Tiantanxili, Beijing 100050, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory of Bacteriology, Rega Institute, Katholieke Universiteit Leuven, Minderbroedersstraat 10, 3000 Leuven, Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Anné
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D048170:Streptomyces lividans / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D014409:Tumor Necrosis Factor-alpha; D046988:Proteasome Endopeptidase Complex