세포내인자로서의 정교한 기능을 하는 molecular chaperone

권오유,송민호 한국생명과학회 1998 생명과학회지 Vol.8 No.2

Molecular chaperone의 발견은 생명과학자들에게 살아있는 세포 내에서 어떻게 생체활성단백질이 만들어지고 유지되는지에 대한 자극과 함께 그것을 증명하기 위한 실험동기를 부여하였다. 초기에는 Molecular chaperone이 nucleosomes의 assembly에 관여하는 단백질을 설명하기 위하여 사용되었으나, 지금은 기본적인 세포생리기능의 하나인 단백질의 folding과 assembly를 돕는 assistant protein으로 주로 사용된다. 단백질합성 뿐만 아니라 단백질수송, oligomeric structure의 assembly와 disassembly, heat shock을 포함한 각종 내, 외부스트래스에 의해서 변성된 단백질의 세로내분화와 회복에도 Molecular chaperone이 관여하고 있다. 그러나 아직까지는 Molecular chaperone들의 3차구조와 그들간의 상호작용에 관한 정보가 부족하여 크게 진전되지 못하고 있지만, 많은 연구자에 의한 정보축적으로 인하여 빠른 시일 내에 Molecular chaperone에 세포내역할이 분명하게밝혀질 것이다. Discovery of molecular chaperone has stimulate cell biologists and thus made it possible to re-examine the processes whereby proteins achieve and maintain their functional conformations within living cells. the term ‘Molecular chaperone’ was first coined to describe one particular protein involved in the assembly of nucleosomes, but the term has now been extended to describe the function of a wide variety of proteins that assist protein transport across membranes, folding of nascent polypeptide, the assembly and disassembly of oligomeric structures, and the recovery or removal of proteins damaged by various environmental stresses including heat shock. Progress of molecular chaperone research is still limited by the lack of 3-dimensional structural information and detailed interacts with taget proteins in the cell. However, several laboratories around the world are attempting to extend our knowledge on the functions of molecular chaperone, and such efforts seem justified to finally provide the answers to the most burning questions shortly.

Molecular chaperone as a sophisticated intracellular membership

Kwon, O-Yu,Shong, Min-ho 충남대학교 생물공학연구소 1999 생물공학연구지 Vol.7 No.-

Molecular chaperone의 발견은 생명과학자들에게 살아있는 세포 내에서 어떻게 생체활성단백질이 만들어지고 유지되는지에 대한 자극과 함께 그것을 증명하기 위한 실험동기를 부여하였다. 초기에는 molecular chaperone이 nucleosomes의 assembly에 관하여는 단백질을 설명하기 위하여 사용되었으나, 지금은 기본적인 세포생리기능의 하나인 단백질의 folding과 assembly를 돕는 assistant protein으로 주로 사용된다. 단백질합성 뿐만 아니라 단백질수송, oligomeric structure의 assembly와 disassembly, heat shock을 포함한 각종 내, 외부스트래스에 의해서 변성된 단백질의 세포내분해와 회복에도 molecular chaperone이 관여하고 있다. 그러나 아직까지는 molecular chaperone들의 3차구조와 그들간의 상호작용에 관한 정보가 부족하여 크게 진전되지 못하고 있지만, 많은 연구자에 의한 정보축적으로 인하여 빠른 시일 내에 molecular chaperone의 세포내역할이 분명하게밝혀질것이다. Discovery of molecular chaperones has stimulate cell biologists and thus made it possible to re-examine the processes whereby proteins achieve and maintain their functional conformations within living cells. The term 'molecular chaperone' was first coined to describe one particular protein involved in the assembly of nucleosomes, but the term has now been extended to describe the function of a wide variety of proteins that assist protein assembly in a wide range of fundamental cellular processes. Besides protein synthesis, these processes include protein transport across membranes, folding of nascent polypeptide, the assembly and disassembly of oligomeric structures, and the recovery or removal of proteins damaged by various environmental stresses including heat shock. Progress of molecular chaperones research is still limited by the lack of 3-dimensional structural information and detailed interacts with target proteins in the cell. However, several laboratories around the world are attempting to extend our knowledge on the functions of molecular chaperone, and such efforts seem justified to finally provide the answers to the most burning questions shortly.

대장균에서 분자 chaperone에 의한 alginate lyase의 가용성 발현 증대

남수완,신은정,이재형,박소림,김형락 한국생명과학회 2007 생명과학회지 Vol.17 No.2

When alginate lyase gene (aly) from Pseudoalteromonas elyakovii was expressed in E. coli, most of the gene product was produced as aggregated insoluble particles known as inclusion bodies. In order to produce a soluble and active form of alginate lyase, E. coli cells were cotransformed with the plasmids designed to permit coexpression of aly together with molecular chaperones such as DnaK/DnaJ/GrpE or GroEL/ES chaperones. The results revealed that the coexpression of aly together with DnaK/DnaJ/GrpE chaperone had a marked effect on the production of this protein as a soluble and active form, presumably through facilitating correct folding of alginate lyase protein. The optimal concentration of L-arabinose for the induction of DnaK/DnaJ/GrpE chaperone was found to be 0.05 mg/ml. When DnaK/DnaJ/GrpE chaperone was coexpressed, about 34% in the total alginate lyase was produced in the soluble fraction. By addition of 10% cetylpyridinium chloride, a clear zone around the colony coexpressing aly and DnaK/DnaJ/GrpE chaperone was formed, indicating that the alginate in the medium was hydrolyzed by active alginate lyase enzyme. E. coli에서 Pseudoalteromonas elyakovii 유래의 alginate lyase 유전자(aly)를 발현시킬 때, 대부분의 단백질이 불용성 내포체 형태로 발현됨을 확인하였다. Alginate lyase를 가용성 활성형으로 생산하기 위해 aly와 DnaK/DnaJ/GrpE 또는 aly와 GroEL/ES을 공발현하는 형질전환체를 얻었다. 공발현 결과, 단백질의 올바른 접힘을 도와주는 DnaK/DnaJ/GrpE chaperone이 가용성 및 활성형의 alginate lyase 생산에 매우 효과적임을 알 수 있었다. DnaK/DnaJ/GrpE chaperone의 발현에 유도제인 L-arabinose 최적 농도는 0.05 mg/ml이었으며, 이러한 공발현에 의해 약 34%의 alginate lyase가 가용성 분획에서 생산되었다. 또한 10%의 cetylpyridinium chloride를 첨가함으로써, 공발현 콜로니 주위에 투명환이 형성됨을 확인할 수 있었고, 이는 활성형 alginate lyase 효소에 의해 alginate가 분해되었음을 시사하였다.

대장균에서 분자 chaperone에 의한 alginate lyase의 가용성 발현 증대

신은정,이재형,박소림,김형락,남수완,Shin, Eun-Jung,Lee, Jae-Hyung,Park, So-Lim,Kim, Hyeung-Rak,Nam, Soo-Wa 한국생명과학회 2007 생명과학회지 Vol.17 No.1

E. coli에서 Pseudoalteromonas elyakovii 유래의 alginate lyase유전자(aly)를 발현시킬 때, 대부분의 단백질이 불용성 내포체 형태로 발현됨을 확인하였다. Alginate lyase를 가용성 활성형으로 생산하기 위해 aly와 DnaK/DnaJ/GrpE 또는 aly와 GroEL/ES을 공발현하는 형질전환체를 얻었다. 공발현 결과, 단백질의 올바른 접힘을 도와주는 DnaK/DnaJ/GrpE chaperone이 가용성 및 활성형의 alginate lyase 생산에 매우 효과적임을 알 수 있었다. DnaK/DnaJ/GrpE chaperone의 발현에 유도제인 L-arabinose 최적 농도는 0.05 mg/ml이었으며, 이러한 공발현에 의해 약 34%의 alginate lyase가 가용성 분획에서 생산되었다. 또한 10%의 cetylpyridinium chloride를 첨가함으로써, 공발현 콜로니 주위에 투명환이 형성됨을 확인할 수 있었고, 이는 활성형 alginate lyase 효소에 의해 alginate가 분해되었음을 시사하였다. When alginate lyase gene (aly) from Pseudoalteromonas elyakovii was expressed in E. coli, most of the gene product was produced as aggregated insoluble particles known as inclusion bodies. In order to produce a soluble and active form of alginate lyase, E. coli cells fore cotransformed with the plasmids designed to permit coexpression of aly together with molecular chaperones such as DnaK/DnaJ/GrpE or GroEL/ES chaperones. The results revealed that the coexpression of aly together with DnaK/DnaJ/GrpE chaperone had a marked effect on the production of this protein as a soluble and active form, presumably through facilitating correct folding of alginate lyase protein. The optimal concentration of L-arabinose for the induction of DnaK/DnaJ/GrpE chaperone was found to be 0.05 mg/ml. When DnaK/DnaJ/GrpE chaperone was coexpressed, about 34% in the total alginate lyase was produced in the soluble fraction. By addition of 10% cetylpyridinium chloride, a clear zone around the colony coexpressing aly and DnaK/DnaJ/GrpE chaperone was formed, indicating that the alginate in the medium was hydrolyzed by active alginate lyase enzyme.

E. coli에서 GroEL/ES chaperone 공발현에 의한 활성형 cyclodextrin glucanotransferase의 생산 증대

권미정,박소림,김병우,김성구,남수완 한국생명과학회 2002 생명과학회지 Vol.12 No.6

Chaperone 분자는 세포 내에서 새로 합성된 polypeptides의 misfolding을 보호하는 역할을 가진다. 이런 chaperone 분자와의 공발현은 활성형 재조합 단백질의 생산을 증가를 기대할 수 있다. 본 연구에서는 E. cozi에서 B. macerans 유래 cyclodextrin glucanotransferase (CGTase)의 활성형 생산에 GroEL/ES chaperone과의 공발현의 효과에 대해 조사하였다. cgt와 groEL/ES 유전자출 발현하는 pTCGT1과 pGro7은 각각 T7 promoter와 araB promoter에 의해 조절되고 이들을 E. coli cell에 co-transformation시켰다. 재조합 E. coli에서 IPTG와 L-arabinose의 최적 농도를 결정하기 위해 행한 결과 1 mM IPTG, 0.3 mg L-arabinose/$m\ell$에서 가장 높은 CGTase 활성을 나타내었다. 그리고 tube에서는 L-arabinose와 IPTG를 각각 0.4~0.5 $OD_{600}$과 0.8~l.0 $OD_{600}$에서 첨가하였을 때 활성형 CGTase의 생산이 증가되었다. GroEL/ES 공발현 조건에서는 가용성 CGTase 활성이 0.7~0.73 unit/$m\ell$로 단독 발현의 0.36~0.56 unit/$m\ell$에 비해 약 1.5 배 정도 증가함을 알 수 있었다. SDS-PAGE 분석에서는 GroEL/ES 공발현 조건에서 총 CGTase의 33.6%정도가 가용성 형태로 생산됨을 알 수 있었다. Molecular chaperones prevent the misfolding of newly synthesized polypeptides in the cell. The coexpression of molecular chaperones could be expected to improve the production of soluble and active recombinant proteins. In this study, the effect of coexpression of E. coli GroEL/ES chaperone on the active production of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in E. coli was investigated. Two plasmids, pTCGT1 and pGro7 in which the cgt and the groEL/ES genes are under the control of 77 promoter and araB promoter, respectively, were co-transformed into E. coli. With a series of cultures of recombinant E. coli cells, the optimal concentrations of IPTG and L-arabinose were found be 1 mM and 0.3 mg/$m\ell$, respectively. When IPTG and L-arabinose were added at 0.8~1.0 $OD_{600}$ and 0.4~0.5 $OD_{600}$, active CGTase production was increased significantly. This coexpression condition resulted in 1.5-fold increased level of soluble CGTase (0.7~0.73 unit/$m\ell$), compared to the level of CGTase in the single expression (0.36~0.56 unit/$m\ell$). An SDS-PACE analysis revealed that about 33.6% of CGTase in the total CGTase protein was found in the soluble fraction by coexpression of GroEL/ES chaperone.

Heat‐induced chaperone activity of serine/threonine protein phosphatase 5 enhances thermotolerance in <i>Arabidopsis thaliana</i>

Park, Jin Ho,Lee, Sun Yong,Kim, Woe Yeon,Jung, Young Jun,Chae, Ho Byoung,Jung, Hyun Suk,Kang, Chang Ho,Shin, Mi Rim,Kim, Sun Young,Su’udi, Mukhamad,Yun, Dae Jin,Lee, Kyun Oh,Kim, Min Gab,Lee, Sang Yeo Blackwell Publishing Ltd 2011 The New phytologist Vol.191 No.3

<P><B>Summary</B></P><P><P>This study reports that <I>Arabidopsis thaliana</I> protein serine/threonine phosphatase 5 (AtPP5) plays a pivotal role in heat stress resistance. A high‐molecular‐weight (HMW) form of AtPP5 was isolated from heat‐treated <I>A. thaliana</I> suspension cells. AtPP5 performs multiple functions, acting as a protein phosphatase, foldase chaperone, and holdase chaperone. The enzymatic activities of this versatile protein are closely associated with its oligomeric status, ranging from low oligomeric protein species to HMW complexes.</P><P>The phosphatase and foldase chaperone functions of AtPP5 are associated primarily with the low‐molecular‐weight (LMW) form, whereas the HMW form exhibits holdase chaperone activity. Transgenic over‐expression of <I>AtPP5</I> conferred enhanced heat shock resistance to wild‐type <I>A. thaliana</I> and a T‐DNA insertion knock‐out mutant was defective in acquired thermotolerance. A recombinant phosphatase mutant (H290N) showed markedly increased holdase chaperone activity.</P><P>In addition, enhanced thermotolerance was observed in transgenic plants over‐expressing H290N, which suggests that the holdase chaperone activity of AtPP5 is primarily responsible for AtPP5‐mediated thermotolerance.</P><P>Collectively, the results from this study provide the first evidence that AtPP5 performs multiple enzymatic activities that are mediated by conformational changes induced by heat‐shock stress.</P></P>

Structural and biochemical analyses reveal ubiquitin C-terminal hydrolase-L1 as a specific client of the peroxiredoxin II chaperone

Lee, Sang Pil,Park, Chan Mi,Kim, Kyung Seok,Kim, Eunji,Jeong, Moonkyung,Shin, Ji-Young,Yun, Chul-Ho,Kim, Kanghwa,Chock, P. Boon,Chae, Ho Zoon Elsevier 2018 Archives of biochemistry and biophysics Vol.640 No.-

<P><B>Abstract</B></P> <P>Peroxiredoxins (Prxs) play dual roles as both thiol-peroxidases and molecular chaperones. Peroxidase activity enables various intracellular functions, however, the physiological roles of Prxs as chaperones are not well established. To study the chaperoning function of Prx, we previously sought to identify heat-induced Prx-binding proteins as the clients of a Prx chaperone. By using His-tagged Prx I as a bait, we separated ubiquitin C-terminal hydrolase-L1 (UCH-L1) as a heat-induced Prx I binding protein from rat brain crude extracts. Protein complex immunoprecipitation with HeLa cell lysates revealed that both Prx I and Prx II interact with UCH-L1. However, Prx II interacted considerably more favorably with UCH-L1 than Prx I. Prx II exhibited more effective molecular chaperone activity than Prx I when UCH-L1 was the client. Prx II interacted with UCH-L1 through its C-terminal region to protect UCH-L1 from thermal or oxidative inactivation. We found that chaperoning via interaction through C-terminal region (specific-client chaperoning) is more efficient than that involving oligomeric structural change (general-client chaperoning). Prx II binds either thermally or oxidatively unfolding early intermediates of specific clients and thereby shifted the equilibrium towards their native state. We conclude that this chaperoning mechanism provides a very effective and selective chaperoning activity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Prx II interacts with UCH-L1 through its C-terminal region. </LI> <LI> Prx II effectively protects UCH-L1 against thermal or oxidative inactivation. </LI> <LI> Oligomeric structural changes are not prerequisite for this chaperoning mechanism. </LI> <LI> This novel chaperoning mechanism is named as specific-client chaperoning. </LI> </UL> </P>

A New Antioxidant with Dual Functions as a Peroxidase and Chaperone in Pseudomonas aeruginosa

An, Byung-Chull,Lee, Seung-Sik,Lee, Eun-Mi,Lee, Jae-Taek,Wi, Seung-Gon,Jung, Hyun-Suk,Park, Woo-Jun,Chung, Byung-Yeoup Korean Society for Molecular and Cellular Biology 2010 Molecules and cells Vol.29 No.2

Thiol-based peroxiredoxins (Prxs) are conserved throughout all kingdoms. We have found that a conserved typical 2-Cys Prx-like protein (PaPrx) from Pseudomonas aeruginosa bacteria displays diversity in its structure and apparent molecular weight (MW), and can act alternatively as a peroxidase and molecular chaperone. We have also identified a regulatory factor involved in this structural and functional switching. Exposure of P. aeruginosa to hydrogen peroxide ($H_2O_2$) causes PaPrx to convert from a high MW (HMW) complex to a low MW (LMW) form, which triggers a chaperone to peroxidase functional switch. This structural switching is primarily guided by either the thioredoxin (Trx) or glutathione (GSH) systems. Furthermore, comparison of our structural data [native and non-reducing polyacrylamide gel electrophoresis (PAGE) analysis, size exclusion chromatography (SEC) analysis, and electron microscopy (EM) observations] and enzymatic analyses (peroxidase and chaperone assay) revealed that the formation of oligomeric HMWcomplex structures increased chaperone activity of PaPrx. These results suggest that multimerization of PaPrx complexes promotes chaperone activity, and dissociation of the complexes into LMW species enhances peroxidase activity. Thus, the dual functions of PaPrx are clearly associated with their ability to form distinct protein structures.

Effect of temperature and denaturation conditions on protein folding assisted by GroEL-GroES chaperonin

배유진,장경진,전숭종,남수완,이재형,김영만,김동은,Bae, Yu-Jin,Jang, Kyoung-Jin,Jeon, Sung-Jong,Nam, Soo-Wan,Lee, Jae-Hyung,Kim, Young-Man,Kim, Dong-Eun Korean Society of Life Science 2007 생명과학회지 Vol.17 No.2

이 연구의 목적은 대장균 분자 샤페론 GroEL의 시험관 내 단백질 접힘에 있어서 반응온도의 영향과 보조샤페론의 필요 여부를 자발적 재접힘이 가능한 온도와 그렇지 않은 온도조건에서 조사하는 것이다. 여러 조건하에서 GroEL에 의한 두 가지 기질 단백질의 재접힘을 반응속도론적으로 조사하기 위하여 GroEL에 의한 단백질 침전생성억제와 변성된 단백질의 재접힘을 광범위하게 조사하였다. 자발적 재접힘이 가능하지 않은 $37^{\circ}C$에서는 ATP와 완전한 GroEL 시스템이 변성된 폴리펩티드의 재접힘을 위하여 필요하다는 것을 확인하였다. 하지만, 자발적 재접힘이 가능한 낮은 온도에서는 자발적 재접힘과 샤페론 의존적 단백질 재접힘이 서로 경쟁하는 것을 알 수 있었다. 따라서 GroEL은 변성된 폴리펩티드의 자발적 접힘 경로를 더 효율적인 단백질 재접힘 경로인 샤페론 의존적 단백질 재접힘 경로로 유도하는 것으로 보인다. The goal of this study is to investigate effects of temperature and co-chaperonin requirement for in vitro protein refolding assisted by E. coli chaperone GroEL under permissive and nonpermissive temperature conditions. In vitro protein refolding of two denatured proteins was kinetically investigated under several conditions in the presence of GroEL. Effects of temperature and GroES-requirement on the process of prevention of protein aggregation and refolding of denatured protein were extensively monitored. We have found that E. coli GroEL chaperone system along with ATP is required for invitro refolding of unfolded polypeptide under nonpermissive temperature of $37^{\circ}C$. However, under permissive condition spontaneous refolding can occur due to lower temperature, which can competes with chaperone-mediated protein refolding via GroEL chaperone system. Thus, GroEL seemed to divert spontaneous refolding pathway of unfolded polypeptide toward chaperone-assisted refolding pathway, which is more efficient protein refolding pathway.

Identification of Chaperones in Freeze Tolerance in Saccharomyces cerevisiae

Mahendran Chinnamara Naicker,조이슬,임하나 한국미생물학회 2012 The journal of microbiology Vol.50 No.5

Exposure to low temperatures reduces protein folding rates and induces the cold denaturation of proteins. Considering the roles played by chaperones in facilitating protein folding and preventing protein aggregation, chaperones must exist that confer tolerance to cold stress. Here, yeast strains lacking individual chaperones were screened for reduced freezing tolerance. In total, 19 of 82 chaperone-deleted strains tested were more sensitive to freeze-thaw treatment than wild-type cells. The reintroduction of the respective chaperone genes into the deletion mutants recovered the freeze tolerance. The freeze sensitivity of the chaperone-knockout strains was also retained in the presence of 20% glycerol.