Identification and Characterization of an Auxin-inducible Protein Kinase, VrCRK1, from Mungbean

권지안,장수철,윤혜섭,Peter B. Kaufman,김성기,김태욱,Bin Goo Kang 한국분자세포생물학회 2004 Molecules and cells Vol.18 No.3

An auxin-inducible protein kinase, VrCRK1, was isolatedby a differential reverse transcriptase-polymerasechain reaction, using mRNAs extracted from auxintreatedmungbean hypocotyls. VrCRK1 exhibits highhomology with plant CDPKs over catalytic domains, however, it does not have any calcium-binding EF-hand which is typically shown in plant CDPKs. Auxin treatment increased the expression level of VrCRK1. However, the increased level was reduced to basal level by treatment with PCIB, an auxin inhibitor. When extracts of mungbean hypocotyls were immunoprecipitated and the resultant immunoprecipitates were used as the enzyme source, kinase activity of VrCRK1 was found, and such activity was also increased by auxin treatment. In transgenic tobacco plants that express VrCRK1, the transcript levels of some auxin-dependent genes were elevated as much as those in wild type plants treated with auxin. These results indicate that gene expression of VrCRK1 is specifically induced by auxin, and that VrCRK1 may play a role in auxin signaling via protein phosphorylation.

Contact Angle and Adhesion Dynamics and Hysteresis on Molecularly Smooth Chemically Homogeneous Surfaces

Chen, Szu-Ying,Kaufman, Yair,Schrader, Alex M.,Seo, Dongjin,Lee, Dong Woog,Page, Steven H.,Koenig, Peter H.,Isaacs, Sandra,Gizaw, Yonas,Israelachvili, Jacob N. American Chemical Society 2017 Langmuir Vol.33 No.38

<P>Measuring truly equilibrium adhesion energies or contact angles to obtain the thermodynamic values is experimentally difficult because it requires loading/unloading or advancing/receding boundaries to be measured at rates that can be slower than 1 nm/s. We have measured advancing-receding contact angles and loading-unloading adhesion energies for various systems and geometries involving molecularly smooth and chemically homogeneous surfaces moving at different but steady velocities in both directions, ±<I>V</I>, focusing on the thermodynamic limit of ±<I>V</I> → 0. We have used the Bell Theory (1978) to derive expressions for the dynamic (velocity-dependent) adhesion energies and contact angles suitable for both (i) dynamic adhesion measurements using the classic Johnson-Kendall-Roberts (JKR, 1971) theory of “contact mechanics” and (ii) dynamic contact angle hysteresis measurements of both rolling droplets and syringe-controlled (sessile) droplets on various surfaces. We present our results for systems that exhibited both steady and varying velocities from <I>V</I> ≈ 10 mm/s to 1 nm/s, where in all cases but one, the advancing (<I>V</I> > 0) and receding (<I>V</I> < 0) adhesion energies and/or contact angles converged toward the same theoretical (thermodynamic) values as <I>V</I> → 0. Our equations for the dynamic contact angles are similar to the classic equations of Blake & Haynes (1969) and fitted the experimental adhesion data equally well over the range of velocities studied, although with somewhat different fitting parameters for the characteristic molecular <I>length/dimension</I> or <I>area</I> and characteristic bond formation/rupture <I>lifetime</I> or <I>velocity</I>. Our theoretical and experimental methods and results unify previous kinetic theories of adhesion and contact angle hysteresis and offer new experimental methods for testing kinetic models in the thermodynamic, <I>quasi-static</I>, limit. Our analyses are limited to kinetic effects only, and we conclude that hydrodynamic, i.e., viscous, and inertial effects do not play a role at the interfacial velocities of our experiments, i.e., <I>V</I> < (1-10) mm/s (for water and hexadecane, but for viscous polymers it may be different), consistent with previously reported studies.</P> [FIG OMISSION]</BR>

Acid growth during the grovitropic response of the leaf - sheath pulvinus of oats ( Avena sativa )

Dong Hern Kim,Peter B . Kaufman 한국응용생명화학회(구 한국농화학회) 1995 한국응용생명화학회 학술발표회 Vol.1995 No.2

Ethylene Biosynthesis in a Chilling-Sensitive Arabidopsis Mutant, chs4-2

( Sun A Kim ),( Seong Ki Kim ),( Peter B. Kaufman ),( June Seung Lee ),( Soo Chul Chang ) 한국식물학회 2004 Journal of Plant Biology Vol.47 No.4

We investigated chilling-induced changes in ethylene levels in Arabidopsis to find plants with distinct patterns of ethylene production in the cold-related biosynthetic pathway. The sensitive mutants identified here included chs1-2, chs4-2, and chs6-2. Among these, plants of the chs4-2 mutant produced more ethylene than did the wild type after both were transferred from 4℃ or 10℃ to 22℃. This mutant also showed less freezing tolerance and more electrolyte leakage than the wild-type plants. Our results suggest a relationship between ethylene biosynthesis and chilling sensitivity in the mutant. To determine which of the enzymes involved in ethylene biosynthesis were induced by chilling, we tested the activities of ACC synthase and ACC oxidase in both mutant and wild-type plants, and found greater activity by ACC synthase as well as a higher ACC content in the mutants after all the plants were transferred from 10℃ to 22℃. However, ACC oxidase activity did not differ between mutant and wild-type plants in response to chilling treatment. Therefore, we conclude that chs4-2 mutants produce more ethylene than do other mutants or the wild type during their recovery from chilling conditions. Furthermore, we believe that ACC synthase is the key enzyme involved in this response.

IPCC AR6 WGI 제2장 주요 내용과 핵심 결과

Jinho Ahn,Sergey K. Gulev,Peter W. Thorne,Frank J. Dentener,Catia M. Domingues,Sebastian Gerland,Daoyi Gong,Darrell S. Kaufman,Hyacinth C. Nnamchi,Johannes Quaas,Juan A. Rivera,Shubha Sathyendranath,S 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10

IPCC 6차보고서 2장에서는 현재의 지구시스템 상태를 진단하는데 촛점을 맞추고 있다. 먼저 기후변화의 주요 요인이 되는 대기 이산화탄소 농도의 경우, 현재의 농도는 최근 2백만 동안 경험하지 못한 수준이며, 상승속도는 최소 80만 년 동안 100년 시간규모에서 가장 높다. 지난 수십 년 동안의 기후시스템의 주요 인자는 수백 년 또는 수천 년 동안 경험하지 못한 수준으로 올라가고 있으며, 최소한 과거 2000년 동안 경험하지 못한 속도로 변하고 있다. 지구평균표면온도(GMST)는 1850-1900년 대비 2011-2020년에 약 1.09도 증가하였는데, 육지에서는 1.59도, 해양에서는 0.88도 상승하였다. 전지구적 물순환은 적어도 1980년 이후 강화되었고, 대규모 대기순환은 20세기 중반 이후 강화되었을 가능성이 높다. 북극 해빙(sea ice)의 연평균과 여름철 면적은 적어도 1850년 이후 최소가 된 것이 확실하다. 육상 빙권에서의 변화는 전반적으로 수백 년에서 수천 년 규모에서 유래가 없을 정도이다. 20세기 이후의 해수면 상승 속도는 백 년의 시간 규모에서 적어도 3000년 동안 가장 빠른데, 상승이 가속화 되고 있다. 해양에서도 과거 수백 년에서 수천 년 동안 유래없는 현상이 감지되고 있는데, 해양생물 변화의 경우 대규모 해양온난화와 해양화학 변화와 일치한다. 육상생물 또한 대규모 온난화와 일치하는 변화를 보이고 있다. 중기플리오세온난기(Mid-Pliocene Warm Period, 3.3-3.0 백만 년 전) 동안 지구의 이산화탄소 농도가 지금과 비슷했으나, 현재의 지구보다는 따뜻했는데, 과거의 온난했던 시기는 미래 기후를 예측하는데 도움을 준다.

Two Expansins, EXP1 and EXPB2, Are Correlated with the Growth and Development of Maize Roots

( Min Jeong Kam ),( Hye Sup Yun ),( Peter B. Kaufman ),( Soo Chul Chang ),( Seong Ki Kim ) 한국식물학회 2005 Journal of Plant Biology Vol.48 No.3

Structure of Seed Storage Protein and Starch Grains in the Endosperm of Rice Seeds

박경수,노영복,Park, Kyoung-Soo,Rho, Young-Bok,Kaufman, Peter B. Korean Society of Electron Microscopy 1988 Applied microscopy Vol.18 No.2

두가지 쌀 품종(品種) 종자(種子)(S-201, IR-8)의 호분층을 주사(走査) 및 투과(透過) 전자현미경(電子顯微鏡)으로 관찰(觀察)하면 구형(球形)과 결정형(結晶形)의 단백질체(蛋白質體)가 있는 것으로 밝혀졌으며, 구형(球形) 단백질체(蛋白質體)는 세포질내(細胞質內)에 존재(存在)하고 결정형(結晶形) 단백질체(蛋白質體)는 액포내(液胞內)에서 관찰(觀察)되었다. 가상적(假想的)인 한발 스트레스로서 열자극 처리(處理)($40^{\circ}C$ 에서 4시간)는 호분층(糊粉層)내에 단백질체(蛋白質體) 수에서 정상적(正常的)인 대조구보다 $40{\sim}50%$ 감소(減少)되었다. 또한 호분층(糊粉層)에서 단백질체(蛋白質體) 수의 감소(減少)는 IR-8품종(品種)보다 S-201품종(品種)에서 더욱 현저(顯著)하게 관찰(觀察)되었다. 열자극 처리(處理)로서 단백질체(蛋白質體) 수의 감소(減少)는 S-201품종(品種)에서 결정형(結晶形) 단백질체(蛋白質體)를 둘러싸고 있는 tonoplast membrane의 손상(損傷)으로 밝혀졌으며, 이런 손상(損傷)은 IR-8품종(品種)에는 좀 덜하다는 것으로 나타났다. 즉 이것은 S-201품종(品種)이 IR-8품종(品種)보다 열 자극(刺戟)(한발 스트레스)에 더욱 민감(敏感)하다는 것으로 사료된다. 두 품종(品種)의 종자(種子) 내배유(內胚乳)에 녹말(綠末)이 가득찬 주사(走査) 전자현미경(電子顯微鏡) 사진(寫眞)은 녹말(綠末)이 내배유(內胚乳)의 중앙(中央)으로부터 사출(査出)되는 hexagonal rods로 구성(構成)되어 있다는 것을 나타낸다. 이러한 hexagonal rods는 rods부터 쉽게 분쇄될 수 있는 triangular sectors로 구성(構成)되어 있으며, 이 sectors들의 각 내부(內部)는 $2{\sim}8$개의 단위(單位)로 구성(構成)되어 있는 커다란 compound starch grains들이 들어 있다. 이것은 쌀 내배유세포(內胚乳細胞)에서 compound starch drains들의 매우 다양한 크기를 설명(說明)하고 있다.

Rates of cavity filling by liquids

Seo, Dongjin,Schrader, Alex M.,Chen, Szu-Ying,Kaufman, Yair,Cristiani, Thomas R.,Page, Steven H.,Koenig, Peter H.,Gizaw, Yonas,Lee, Dong Woog,Israelachvili, Jacob N. National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.32

<P>Understanding the fundamental wetting behavior of liquids on surfaces with pores or cavities provides insights into the wetting phenomena associated with rough or patterned surfaces, such as skin and fabrics, as well as the development of everyday products such as ointments and paints, and industrial applications such as enhanced oil recovery and pitting during chemical mechanical polishing. We have studied, both experimentally and theoretically, the dynamics of the transitions from the unfilled/partially filled (Cassie-Baxter) wetting state to the fully filled (Wenzel) wetting state on intrinsically hydrophilic surfaces (intrinsic water contact angle <90 degrees, where the Wenzel state is always the thermodynamically favorable state, while a temporary metastable Cassie-Baxter state can also exist) to determine the variables that control the rates of such transitions. We prepared silicon wafers with cylindrical cavities of different geometries and immersed them in bulk water. With bright-field and confocal fluorescence microscopy, we observed the details of, and the rates associated with, water penetration into the cavities from the bulk. We find that unconnected, reentrant cavities (i.e., cavities that open up below the surface) have the slowest cavity-filling rates, while connected or non-reentrant cavities undergo very rapid transitions. Using these unconnected, reentrant cavities, we identified the variables that affect cavity-filling rates: (i) the intrinsic contact angle, (ii) the concentration of dissolved air in the bulk water phase (i.e., aeration), (iii) the liquid volatility that determines the rate of capillary condensation inside the cavities, and (iv) the presence of surfactants.</P>

Blueberry Intake Alters Skeletal Muscle and Adipose Tissue Peroxisome Proliferator-Activated Receptor Activity and Reduces Insulin Resistance in Obese Rats

E. Mitchell Seymour,Ignasia I. Tanone,Daniel E. Urcuyo-Llanes,Sarah K. Lewis,Ara Kirakosyan,Michael G. Kondoleon,Peter B. Kaufman,Steven F. Bolling 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.12

Metabolic syndrome can precede the development of type 2 diabetes and cardiovascular disease and includes phenotypes such as obesity, systemic inflammation, insulin resistance, and hyperlipidemia. A recent epidemiological study indicated that blueberry intake reduced cardiovascular mortality in humans, but the possible genetic mechanisms of this effect are unknown. Blueberries are a rich source of anthocyanins, and anthocyanins can alter the activity of peroxisome proliferatoractivated receptors (PPARs), which affect energy substrate metabolism. The effect of blueberry intake was assessed in obesity-prone rats. Zucker Fatty and Zucker Lean rats were fed a higher-fat diet (45% of kcal) or a lower-fat diet (10% of kcal)containing 2% (wt/wt) freeze-dried whole highbush blueberry powder or added sugars to match macronutrient and calorie content. In Zucker Fatty rats fed a high-fat diet, the addition of blueberry reduced triglycerides, fasting insulin, homeostasis model index of insulin resistance, and glucose area under the curve. Blueberry intake also reduced abdominal fat mass,increased adipose and skeletal muscle PPAR activity, and affected PPAR transcripts involved in fat oxidation and glucose uptake/oxidation. In Zucker Fatty rats fed a low-fat diet, the addition of blueberry also significantly reduced liver weight, body weight, and total fat mass. Finally, Zucker Lean rats fed blueberry had higher body weight and reduced triglycerides, but all other measures were unaffected. In conclusion, whole blueberry intake reduced phenotypes of metabolic syndrome in obesityprone rats and affected PPAR gene transcripts in adipose and muscle tissue involved in fat and glucose metabolism.

Altered Hyperlipidemia, Hepatic Steatosis, and Hepatic Peroxisome Proliferator-Activated Receptors in Rats with Intake of Tart Cherry

E. Mitchell Seymour,Andrew A.M. Singer,Ara Kirakosyan,Daniel E. Urcuyo-Llanes,Peter B. Kaufman,Steven F. Bolling 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.2

Elevated plasma lipids, glucose, insulin, and fatty liver are among components of metabolic syndrome, a phe-notypic pattern that typically precedes the development of Type 2 diabetes. Animal studies show that intake of anthocyaninsreduces hyperlipidemia, obesity, and atherosclerosis and that anthocyanin-rich extracts may exert these effects in associationwith altered activity of tissue peroxisome proliferator-activated receptors (PPARs). However, studies are lacking to test thiscorrelation using physiologically relevant, whole food sources of anthocyanins. Tart cherries are a rich source of anthocyanins,and whole cherry fruit intake may also affect hyperlipidemia and/or affect tissue PPARs. This hypothesis was tested in theDahl Salt-Sensitive rat having insulin resistance and hyperlipidemia. For 90 days, Dahl rats were pair-fed AIN-76a-based di-ets supplemented with either 1% (wt:wt) freeze-dried whole tart cherry or with 0.85% additional carbohydrate to matchmacronutrient and calorie provision. After 90 days, the cherry-enriched diet was associated with reduced fasting blood glu-cose, hyperlipidemia, hyperinsulinemia, and reduced fatty liver. The cherry diet was also associated with significantly en-hanced hepatic PPAR-. mRNA, enhanced hepatic PPAR-. target acyl-coenzyme A oxidase mRNA and activity, and in-creased plasma antioxidant capacity. In conclusion, physiologically relevant tart cherry consumption reduced several phenotypicrisk factors that are associated with risk for metabolic syndrome and Type 2 diabetes. Tart cherries may represent a wholefood research model of the health effects of anthocyanin-rich foods and may possess nutraceutical value against risk factorsfor metabolic syndrome and its clinical sequelae.