title: SUMO as a solubility tag and in vivo cleavage of SUMO fusion proteins with Ulp1.
abstract: Expression of proteins in E. coli is often plagued by insolubility of the protein of interest. A solution to this problem is the expression of proteins as fusions to solubility tags such as the SUMO protein. SUMO fusion proteins can be cleaved to remove the SUMO moiety using SUMO-specific proteases such as Ulp1. Here, we describe the use of vectors for the expression of recombinant proteins in E. coli as fusions to the Drosophila SUMO protein. This includes a vector that encodes not only the SUMO tagged protein of interest but also SUMO-tagged Ulp1. Coexpression of these two proteins results in the in vivo cleavage of the protein of interest from the SUMO tag, while still leaving the protein of interest in a form that can be purified from a soluble cell lysate by nickel affinity chromatography.
authors.affiliation: Department of Chemistry & Biochemistry, Molecular Biology Institute, University of California, 607 Charles E. Young Drive, East, Los Angeles, CA, 90095-1569, USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Kuo
authors.forename: Minghua
authors.initials: M
authors.lastname: Nie
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Courey
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods*; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005822:Genetic Vectors; D008967:Molecular Biology / Q000379:methods*; D011485:Protein Binding; D014176:Protein Biosynthesis / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000302:isolation & purification*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000737:chemistry; D012995:Solubility
chemical_list: D011993:Recombinant Fusion Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D003546:Cysteine Endopeptidases; C118083:Ulp1 protease