• Molecules and Cells
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• 제40권1호
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• pp.1-9
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• 2017

Serine and arginine-rich (SR) proteins are RNA-binding proteins (RBPs) known as constitutive and alternative splicing regulators. As splicing is linked to transcriptional and post-transcriptional steps, SR proteins are implicated in the regulation of multiple aspects of the gene expression program. Recent global analyses of SR-RNA interaction maps have advanced our understanding of SR-regulated gene expression. Diverse SR proteins play partially overlapping but distinct roles in transcription-coupled splicing and mRNA processing in the nucleus. In addition, shuttling SR proteins act as adaptors for mRNA export and as regulators for translation in the cytoplasm. This mini-review will summarize the roles of SR proteins as RNA binders, regulators, and connectors from transcription in the nucleus to translation in the cytoplasm.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1022-1027
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• 2005

Based on plasmid display technology by the complexes of fusion protein and the encoding plasmid DNA, an in vitro selection method for high affinity DNA-binding protein was developed and experimentally demonstrated. The GAL4 DNA-binding domain (GAL4 DBD) was selected as a model DNA-binding protein, and enhanced green fluorescent protein (EGFP) was used as an expression reporter for the selection of target proteins. Error prone PCR was conducted to construct a mutant library of the model. Based on the affinity decrease with increased salt concentration, mutants of GAL4 DBD having high affinity were selected from the mutant protein library of protein-encoding plasmid complex by this method. Two mutants of (Lys33Glu, Arg123Lys, Ile127Lys) and (Ser47Pro, Ser85Pro) having high affinity were obtained from the first generation mutants. This method can be used for rapid in vitro selection of high affinity DNA-binding proteins, and has high potential for the screening of high affinity DNA-binding proteins in a sequence-specific manner.

• 미생물학회지
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• 제26권4호
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• pp.291-297
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• 1988

신호배열 돌연변이인 rbsB 103는 전구체 리보스 결합단백질을 세포질내에 축적시키고, rbsB 106 복귀유전자는 이 전구체를 숙성 가능하게 하여 페리플라슴으로 수송되게 한다.(Iida el at., 1985, Park, el at., 1988). 본고에서는 rbsB 유전자의 세 allele, rbsB, rbsB 103와 rbsB 106를 이들이 코딩하는 단백질을 대량생산 하그l자 람다 P 프로모터 조절하에 클론하고 나아가서 다섯종의 단백질을 순수정제하였다.. 전구체 단백질의 pI는 8.0, 숙성단백질의 $P_{L}$는 7.5임을 밝혔다. 순수정제된 단백질의 아마노 말단의 아미노산 배열을 결정하여 DNA 염기서열로부터 밝혀진 아미노산 변화를 확인하였다.

• 한국수산과학회지
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• 제31권5호
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• pp.774-778
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• 1998

동물성장인자인 insulin-like growth factor-I (IGF-I)이 조피볼락의 성장 및 혈액중에 존재하는 IGF binding proteins (IGFBPs)에 미치는 영향을 검토하기 위하여 human recombinant IGF-I을 투여하여 분석한 결과, 절식중의 조피볼락 체중은 IGF-I 투여군이 생리식염수만 투여한 대조군 보다 체중 증가효과가 있었으며, 혈액중 glucose농도는 IGF-I의 투여군이 혈당저하효과를 나타내었다. 그리고 혈액중 IGFBP-3는 IGF-I투여군에서 증가하였으며, IGFBP-1은 감소하였다.

• Molecules and Cells
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• 제21권3호
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• pp.376-380
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• 2006

Gene expression is regulated in large part at the level of transcription under the control of sequence-specific transcriptional regulatory proteins. Therefore, the ability to affect gene expression at will using sequencespecific artificial transcription factors would provide researchers with a powerful tool for biotechnology research and drug discovery. Previously, we isolated 56 novel sequence-specific DNA-binding domains from the human genome by in vivo selection. We hypothesized that these domains might be more useful for regulating gene expression in higher eukaryotic cells than those selected in vitro using phage display. However, an unpredictable factor, termed the "context effect", is associated with the construction of novel zinc finger transcription factors--- DNA-binding proteins that bind specifically to 9-base pair target sequences. In this study, we directly selected active artificial zinc finger proteins from a zinc finger protein library. Direct in vivo selection of constituents of a zinc finger protein library may be an efficient method for isolating multi-finger DNA binding proteins while avoiding the context effect.

• Molecules and Cells
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• 제41권10호
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• pp.889-899
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• 2018

Intrinsically disordered proteins (IDPs) are highly unorthodox proteins that do not form three-dimensional structures under physiological conditions. The discovery of IDPs has destroyed the classical structure-function paradigm in protein science, 3-D structure = function, because IDPs even without well-folded 3-D structures are still capable of performing important biological functions and furthermore are associated with fatal diseases such as cancers, neurodegenerative diseases and viral pandemics. Pre-structured motifs (PreSMos) refer to transient local secondary structural elements present in the target-unbound state of IDPs. During the last two decades PreSMos have been steadily acknowledged as the critical determinants for target binding in dozens of IDPs. To date, the PreSMo concept provides the most convincing structural rationale explaining the IDP-target binding behavior at an atomic resolution. Here we present a brief developmental history of PreSMos and describe their common characteristics. We also provide a list of newly discovered PreSMos along with their functional relevance.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.247-254
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• 2015

In this presentation, I describe the expression and purification of the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a commercially available double cistronic vector, pACYCDuet-1, to express the receptor heterodimer in a single cell as the soluble form. I describe here the expression and characterization of a biologically active heterodimer composed of the liver X receptor β-ligand binding domain and retinoid X receptor α-ligand binding domain. Although many of these proteins were previously seen to be produced in E. coli as insoluble aggregates or "inclusion bodies", I show here that as a form of heterodimer they can be made in soluble forms that are biologically active. This suggests that co-expression of the liver X receptor β-ligand binding domain with its binding partner improves the solubility of the complex and probably assists in their correct folding, thereby functioning as a type of molecular chaperone.

• Journal of Plant Biotechnology
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• 제38권2호
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• pp.137-142
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• 2011

Auxin is a group of small natural and synthetic molecules having diverse regulatory functions in plant growth and development. In this review, two auxin binding proteins identified by biochemical experiments to measure their auxin binding activities and biochemical functions are described. ABP1, a 22 kDa auxin binding protein, shows strong auxin binding affinity and possibly plays an important role in plant development, although its biochemical function are still unclear. ABP57, a 57 kDa soluble protein from rice shoots, has both of IAA binding activity and the plasma membrane proton pump activation. Although it is yet to be accomplished, the improvement of agronomic traits using auxin binding proteins is worth to be considered, since auxin is known to be related to such a diverse crop traits.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.82-86
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• 1998

The maltose binding protein (MBP) fusion protein system is a versatile tool to express and isolate recombinant proteins in E. coli. In this system, MBP fusion proteins are efficiently isolated from whole cell lysate using amylose conjugated agarose beads and then eluted by competition with free maltose. Since MBP is a rather large molecule (∼42 kDa), for further experiments, the MBP part is usually proteolytically cleaved from the fusion protein and subsequently removed by ion-exchange chromatography or rebinding to amylose columns after washing out excess and MBP-bound maltose. In the present study, we have developed an improved method for the removal of cleaved MBP, which is advantageous over conventional methods. In this method, factor Xa cleaved MBP fusion proteins were incubated with Sepharose beads conjugated with MBP specific monoclonal antibodies and then precipitated buy centrifugation, resulting in highly purified proteins in the supernatant.

• Animal cells and systems
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• 제8권1호
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• pp.49-55
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• 2004

In vertebrates, multisubunit cofactors regulate gene expression through interacting with cell-type- and gene-specific DNA-binding proteins in a chromatin-selective manner. ADD1/SREBP1c regulates fatty acid metabolism and insulin-dependent gene expression through binding to SRE and E-box motif with dual DNA binding specificity. Although its transcriptional and post-translational regulation has been extensively studied, its regulation by interacting proteins is not well understood. To identify cellular proteins that associate with nuclear form of ADD1/SEBP1c, we employed the GST pull-down system with Hela cell nuclei extract. In this study, we demonstrated that Ku proteins interact specifically with ADD1/SREP1c protein. GST pull-down combined with peptide sequencing analysis revealed that Ku80 binds to ADD1/SREBP1c in vitro. Additionally, western blot analysis showed that Ku70, a heterodimerizing partner of Ku80, also associates with ADD1/SREBP1c. Furthermore, co-transfection of Ku70/Ku80 with ADD1/SREBP1c enhanced the transcriptional activity of ADD1/SREBP1c. Taken together, these results suggest that the Ku proteins might be involved in the lipogenic and/or adipogenic gene expression through interacting with ADD1/SREBP1c.