title: Soluble expression and stability enhancement of transcription factors using 30Kc19 cell-penetrating protein.
abstract: Transcription factors have been studied as an important drug candidate. Ever since the successful generation of induced pluripotent stem cells (iPSCs), there has been tremendous interest in reprogramming transcription factors. Because of the safety risks involved in a virus-based approach, many researchers have been trying to deliver transcription factors using nonintegrating materials. Thus, delivery of transcription factors produced as recombinant proteins in E. coli was proposed as an alternative method. However, the low level of soluble expression and instability of such recombinant proteins are potential barriers. We engineered a Bombyx mori 30Kc19 protein as a fusion partner for transcription factors to overcome those problems. We have previously reported that 30Kc19 protein can be produced as a soluble form in E. coli and has a cell-penetrating property and a protein-stabilizing effect. Transcription factors fused with 30Kc19 (Oct4-30Kc19, Sox2-30Kc19, c-Myc-30Kc19, L-Myc-30Kc19, and Klf4-30Kc19) were produced as recombinant proteins. Interestingly, Oct4 and L-Myc were expressed as a soluble form by conjugating with 30Kc19 protein, whereas Oct4 alone and L-Myc alone aggregated. The 30Kc19 protein also enhanced the stability of transcription factors both in vitro and in cells. In addition, 30Kc19-conjugated transcription factors showed rapid delivery into cells and transcriptional activity significantly increased. Overall, 30Kc19 protein conjugation simultaneously enhanced soluble expression, stability, and transcriptional activity of transcription factors. We propose that the conjugation with 30Kc19 protein is a novel approach to solve the technical bottleneck of gene regulation using transcription factors.
authors.affiliation: Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, 151-744, Republic of Korea.
authors.forename: Jina
authors.initials: J
authors.lastname: Ryu
authors.affiliation: The School of Chemical and Biological Engineering, Seoul National University, Seoul, 151-744, Republic of Korea.
authors.forename: Hee Ho
authors.initials: HH
authors.lastname: Park
authors.affiliation: Department of Medical Biomaterials Engineering, Kangwon National University, Chuncheon, 200-701, Republic of Korea.
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: The School of Chemical and Biological Engineering, Seoul National University, Seoul, 151-744, Republic of Korea.
authors.forename: Hong Jai
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Division of Bioengineering, Incheon National University, Incheon, 406-772, Republic of Korea.
authors.forename: Won Jong
authors.initials: WJ
authors.lastname: Rhee
authors.affiliation: Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, 151-744, Republic of Korea. thpark@snu.ac.kr.|The School of Chemical and Biological Engineering, Seoul National University, Seoul, 151-744, Republic of Korea. thpark@snu.ac.kr.|Advanced Institutes of Convergence Technology, Suwon, 443-270, Republic of Korea. thpark@snu.ac.kr.
authors.forename: Tai Hyun
authors.initials: TH
authors.lastname: Park
mesh_terms: D000818:Animals; D012831:Bombyx; D057846:Cell-Penetrating Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D015202:Protein Engineering; D055550:Protein Stability; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: D057846:Cell-Penetrating Peptides; D019476:Insect Proteins; C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors
keywords: 30Kc19 protein; Cell-penetrating property; Protein stability; Recombinant protein; Soluble expression; Transcription factor