128,972 research outputs found
KIF14 and citron kinase act together to promote efficient cytokinesis
No full textMultiple mitotic kinesins and microtubule-associated proteins (MAPs) act in concert to direct cytokinesis (Glotzer, M. 2005. Science. 307:1735-1739). In anaphase cells, many of these proteins associate with an antiparallel array of microtubules termed the central spindle. The MAP and microtubule-bundling protein PRC1 (protein-regulating cytokinesis 1) is one of the key molecules required for the integrity of this structure (Jiang, W., G. Jimenez, N.J. Wells, T.J. Hope, G.M. Wahl, T. Hunter, and R. Fukunaga. 1998. Mol. Cell. 2:877-885; Mollinari, C., J.P. Kleman, W. Jiang, G. Schoehn, T. Hunter, and R.L. Margolis. 2002. J. Cell Biol. 157:1175-1186). In this study, we identify an interaction between endogenous PRC1 and the previously uncharacterized kinesin KIF14 as well as other mitotic kinesins (MKlp1/CHO1, MKlp2, and KIF4) with known functions in cytokinesis (Hill, E., M. Clarke, and F.A. Barr. 2000. EMBO J. 19:5711-5719; Matuliene, J., and R. Kuriyama. 2002. Mol. Biol. Cell. 13:1832-1845; Kurasawa, Y., W.C. Earnshaw, Y. Mochizuki, N. Dohmae, and K. Todokoro. 2004. EMBO J. 23:3237-3248). We find that KIF14 targets to the central spindle via its interaction with PRC1 and has an essential function in cytokinesis. In KIF14-depleted cells, citron kinase but not other components of the central spindle and cleavage furrow fail to localize. Furthermore, the localization of KIF14 and citron kinase to the central spindle and midbody is codependent, and they form a complex depending on the activation state of citron kinase. Contrary to a previous study (Di Cunto, F., S. Imarisio, E. Hirsch, V. Broccoli, A. Bulfone, A. Migheli, C. Atzori, E. Turco, R. Triolo, G.P. Dotto, et al. 2000. Neuron. 28:115-127), we find a general requirement for citron kinase in human cell division. Together, these findings identify a novel pathway required for efficient cytokinesis
Cancer -- 1959-68 -- Correspondence, General -- letter, 1961-11-20
No full textLetter from Citron, Robert R. to Sabin, Albert B. dated 1961-11-20.Sabin Collection Fair Use Policy</a
Citron is not essential for RLC phosphorylation.
No full text<p><b>(A)</b> Immunofluorescent localization of DNΑ (blue) and phospho-RLC (green) in Citron depleted cells. Notice the membrane blebs in the telophase furrow as well as the anti-phospho-RLC antibody staining in the midbody. Scale bar = 5 µm. <b>(B)</b> Depletion of Citron probably affects the structure of telophase midbodies. S2 cells were depleted of Citron by treatment with RNAi for 5 days and then fixed and stained with an anti-phospho-RLC antibody. Late telophase cells were scored for antibody staining (mean, ±SE for 30 cells). While less than half of all control cells were stained, nearly all Citron depleted cells were stained.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Determinants Factor of the Captive Breeding success of Citron-crested cockatoo (Cacatua sulphurea citrinocristata, Fraser 1844)
No full textCitron-crested cockatoo (Cacatua sulphurea citrinocristata) is one of endemic bird which endangered in Sumba islands and protected by in law. The study was aimed to analyze the determinants factor of the captive breeding success of citron-crested cockatoo. The research was conducted in January-March 2018, in Mega Bird and Orchid Farm Bogor, Ragunan Zoo, Rahardjo Bird Farm Solo, and Cikembulan Zoo. Determinant factor of the captive breeding success of citron-crested cockatoo were analyze using PCA with SPSS 22 software. The main components which are important factors for captive breeding success of Citron-crested cockatoo were breeding techniques (feed, time of handling, the number of productive parent and capital), condition of citron-crested cockatoo cage (temperature and humidity) and human resources (duration time of the breeding and knowledge of the keeper). Keywords: captive breeding, citron-crested cockatoo, principal component </p
Citron binds to PSD-95 at glutamatergic synapses on inhibitory neurons in the hippocampus
No full textSynaptic NMDA-type glutamate receptors are anchored to the second of three PDZ (PSD-95/Discs large/ZO-1) domains in the postsynaptic density (PSD) protein PSD-95. Here, we report that citron, a protein target for the activated form of the small GTP-binding protein Rho, preferentially binds the third PDZ domain of PSD-95. In GABAergic neurons from the hippocampus, citron forms a complex with PSD-95 and is concentrated at the postsynaptic side of glutamatergic synapses. Citron is expressed only at low levels in glutamatergic neurons in the hippocampus and is not detectable at synapses onto these neurons. In contrast to citron, p135 SynGAP, an abundant synaptic Ras GTPase-activating protein that can bind to all three PDZ domains of PSD-95, and Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) are concentrated postsynaptically at glutamatergic synapses on glutamatergic neurons. CaM kinase II is not expressed and p135 SynGAP is expressed in less than half of hippocampal GABAergic neurons. Segregation of citron into inhibitory neurons does not occur in other brain regions. For example, citron is expressed at high levels in most thalamic neurons, which are primarily glutamatergic and contain CaM kinase II. In several other brain regions, citron is present in a subset of neurons that can be either GABAergic or glutamatergic and can sometimes express CaM kinase II. Thus, in the hippocampus, signal transduction complexes associated with postsynaptic NMDA receptors are different in glutamatergic and GABAergic neurons and are specialized in a way that is specific to the hippocampus
Molecular cloning, expression and functional analyses of citron kinase in zebrafish embryos
No full textCitron kinase (CRIK) 屬於絲胺酸/酥胺酸磷酸激酶，並為已活化Rho的下游作用蛋白之一。若於體外培養之哺乳細胞中過度表現喪失功能之CRIK突變種會造成細胞分裂的缺陷，此結果顯示CRIK會影響細胞分裂，其於細胞分裂溝及神經組織之聚集更增加其調控細胞分裂及神經發育之可能性。在果蠅發育過程CRIK雖為各類組織細胞質分裂所必需，而CRIK基因剔除老鼠胚胎早期可發育並出生，但於出生後伴隨明顯神經細胞分裂缺陷和凋亡而死亡。CRIK基因可能在不同物種間有差異或有功能相近之同源基因存在，而導致其在不同物種之功能差異，為探討CRIK在發育過程的基因表現及其功能，我們在模式動物斑馬魚中以in silica cloning和RACE方式選殖出斑馬魚CRIK基因(zcrik)，比較分析其與其他物種CRIK蛋白質序列，利用RT-PCR偵測到成魚腦、眼睛、腎臟、胰臟、卵巢及睪丸組織中皆有zcrik的表現，在原位雜合試驗(in situ hybridization)中可見在發育24小時胚中zcrik表現多在細胞具有高度增殖的區域，如神經先驅細胞等，此現象與先前發表在老鼠表現模式相類似。為了進一步探討zcrik在斑馬魚發育的功能，我們顯微注射morpholino oligonucleotides (MO)至一胞期胚來抑制zcrik mRNA之轉譯，結果顯示zcrik-MO處理過之胚在發育六小時內死亡率較對照組高，並於早期細胞分裂時期有分裂不完整與不正常分裂情形發生，此分裂嚴重受干擾的胚亦在之後細胞遷移過程產生障礙，使得胚無法繼續正常發育而死亡，而存活之胚在受精後24小時觀察其外觀上有明顯無頭和神經管消失等缺陷發生，此結果和先前研究中指出CRIK對神經細胞分裂發育有影響相呼應，再則此等胚之缺陷與過度腹部化(ventralized)的胚型態相類似，由此推測z CRIK在胚發育時期不僅具有調節細胞分裂與神經發育的功能，對於斑馬魚的原腸胚發育過程及背腹部化亦有一定程度的影響。Citron kinase (CRIK) belongs to an evolutionarily conserved family of serine-threonine kinases and is a target molecule for activated Rho. CRIK has been suggested to be involved in regulating cytokinesis in mammalian cells due to the inhibition of cytokinesis by overexpressing dominant negative CRIK. It accumulates at the cleavage furrow and neuronal tissues that implies its roles in early development and neurogenesis. In Drosophila melanogaster, CRIK is essential for normal cell division in all tissue of Drosophila, while the knock out citron kinase allows early embryonic development, but shows defective neurogenesis in mice. To further study the role of CRIK in development, we utilized the recently developed vertebrate model, zebrafish. In this study, we first isolated the zebrafish citron kinase (zcrik) by in silica cloning and RACE experiments. Secondly, the zcrik expression patterns were examined using in situ hybridization and RT-PCR. We found that zcrik mRNA was detected by RT-PCR in adult zebrafish tissues including brain, eye, ovary, testis, kidney, spleen and gill. Whole-mount in situ hybridization of different developmental stages of zebrafish embryos revealed that zcrik expressed in the entire embryo until 18 hour post fertilization and the expression of zcrik mRNA was limit to the proliferate neuroblasts and tissues that is consistent with the expression pattern in mice. Lastly, to evaluate the functions of CRIK in zebrafish development, we applied etopic expression analysis and morpholino oligonucleotides (MO) knockdown to the developing zebrafish embryos. Functional analysis results demonstrated that gain or loss of function of zCRIK resulted defects in cytokinesis, epiboly formation and embryonic death. In addition, the MO-knockdown resulted in severe defects in CNS with little or no head structure formation, which are the characteristics of ventralized embryos at 24 hpf. These results suggest that, in addition to cytokinesis and neuronal development, citron kinase is also essential for gastrulation progressing and may be involved in dorsal-ventral patterning during development.CONTENTS
CONTENTS………………………………………………………………………Ⅰ
LIST OF TABLE……………………………………………………………………Ⅲ
LIST OF FIGURES………………………………………………………………Ⅳ
中文摘要……………………………………………………………………………1
ABSTRACT…………………………………………………………………………2
INTRODUCTION……………………………………………………………4
MATERIALS AND METHODS…………………………………………………9
Cloning of citron kinase cDNA……………………………………………………9
Blasting…………………………………………………………………………9
RNA isolation…………………………………………………………………9
Single-strand cDNA synthesis ……………………………………………10
PCR amplification……………………………………………………………11
Purification of PCR products and subcloning……………………11
Mini-preparation of plasmid DNA………………………………………12
Expression vector construction and in vitro transcription………12
Subcloning of zCRIK kinase domain fragment into T7TS expression vector12
Synthesis of mRNA of zcrik-k………………………………………………12
Antisense Morpholino design and preparation…………………………………14
Microinjection and observation…………………………………………………14
Whole mount in situ hybridization……………………………………………15
Staining of actin cytoskeleton…………………………………………………15
RESULTS…………………………………………………………………………16
Isolation of the zebrafish citron kinase homolog………………………………16
Expression of zebrafish citron kinase during development……………………18
Overexpression zebrafish citron kinase domain during development…………19
Knockdown zebrafish citron kinase by morpholino antisense oligonucleotides…19
DISCUSSION………………………………………………………………………23
REFERENCES……………………………………………………………………33
TABLE………………………………………………………………………………42
FIGURES…………………………………………………………………………4
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
- …
