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961.
Julie?Webber Margaret?E.?JohnstonEmail author Alan?H.?Wearing 《In vitro cellular & developmental biology. Plant》2003,39(2):139-141
Summary
Caustis blakei is an attractive cut foliage plant harvested from the wild in Australia and marketed under the name of koala fern. Previous
attempts to propagate large numbers of this plant have been unsuccessful. The effect of four light irradiances on organogenesis
from compact and friable callus of C. blakei was studied for 21 wk. Both callus types produced numerous primordial shoots but many failed to develop into green plantlets.
However, significantly more primordial shoots and green plantlets developed on the friable callus than on the compact callus,
and significantly more green plantlets were regenerated under the higher photon irradiances of 200 and 300 μmol m−2s−1 than under the lower irradiances of 100 and 150 μmol m−2s−1. The compact callus produced its maximum number of green plantlets early in the experiment (after 9 wk), while the friable
callus continued to produce primordial shoots and green plantelets throughout the period of the experiment, and reached its
maximum production of green plantlets at 21 wk under the irradiance of 300 μmol m−2s−1. Organogenesis from friable callus under high irradiance (300 μmol m−2s−1) offers an efficient propagation method for C. blakei. 相似文献
962.
Huang M Rigby AC Morelli X Grant MA Huang G Furie B Seaton B Furie BC 《Nature structural biology》2003,10(9):751-756
In a calcium-dependent interaction critical for blood coagulation, vitamin K-dependent blood coagulation proteins bind cell membranes containing phosphatidylserine via gamma-carboxyglutamic acid-rich (Gla) domains. Gla domain-mediated protein-membrane interaction is required for generation of thrombin, the terminal enzyme in the coagulation cascade, on a physiologic time scale. We determined by X-ray crystallography and NMR spectroscopy the lysophosphatidylserine-binding site in the bovine prothrombin Gla domain. The serine head group binds Gla domain-bound calcium ions and Gla residues 17 and 21, fixed elements of the Gla domain fold, predicting the structural basis for phosphatidylserine specificity among Gla domains. Gla domains provide a unique mechanism for protein-phospholipid membrane interaction. Increasingly Gla domains are being identified in proteins unrelated to blood coagulation. Thus, this membrane-binding mechanism may be important in other physiologic processes. 相似文献
963.
Cbl-associated protein (CAP) is an adaptor protein that plays important roles in both signal transduction and cytoskeleton rearrangement. Alternative splicing of the gene SORBS1 results in multiple isoforms of CAP protein. We report here the cloning of 3 new CAP isoforms, CAP2, CAP3, and CAP4, from mouse adipose tissue. RT-PCR analyses reveal that the isoform mRNAs are differentially expressed. CAP2, CAP3, and CAP4 contain a coiled-coil domain. In addition, CAP4 contains a proline-rich region, part of which exists in CAP3. Coimmunoprecipitation experiments show that CAP4 forms a homodimeric complex. While these new isoforms similarly interact with Cbl, they exhibit varied binding specificity toward vinculin. In contrast to CAP1 and CAP2, CAP4 does not interact with vinculin, and CAP3 binds with low affinity. Immunofluorescence analysis demonstrates differential subcellular localization of Myc-tagged CAP isoforms in 3T3-L1 adipocytes. These results suggest that these new isoforms of CAP might play different signaling roles. 相似文献
964.
Disruption of the Fanconi anemia-BRCA pathway in cisplatin-sensitive ovarian tumors 总被引:22,自引:0,他引:22
Taniguchi T Tischkowitz M Ameziane N Hodgson SV Mathew CG Joenje H Mok SC D'Andrea AD 《Nature medicine》2003,9(5):568-574
Ovarian tumor cells are often genomically unstable and hypersensitive to cisplatin. To understand the molecular basis for this phenotype, we examined the integrity of the Fanconi anemia-BRCA (FANC-BRCA) pathway in those cells. This pathway regulates cisplatin sensitivity and is governed by the coordinate activity of six genes associated with Fanconi anemia (FANCA, FANCC, FANCD2, FANCE, FANCF and FANCG) as well as BRCA1 and BRCA2 (FANCD1). Here we show that the FANC-BRCA pathway is disrupted in a subset of ovarian tumor lines. Mono-ubiquitination of FANCD2, a measure of the function of this pathway, and cisplatin resistance were restored by functional complementation with FANCF, a gene that is upstream in this pathway. FANCF inactivation in ovarian tumors resulted from methylation of its CpG island, and acquired cisplatin resistance correlated with demethylation of FANCF. We propose a model for ovarian tumor progression in which the initial methylation of FANCF is followed by FANCF demethylation and ultimately results in cisplatin resistance. 相似文献
965.
RAGE mediates amyloid-beta peptide transport across the blood-brain barrier and accumulation in brain 总被引:21,自引:0,他引:21
Deane R Du Yan S Submamaryan RK LaRue B Jovanovic S Hogg E Welch D Manness L Lin C Yu J Zhu H Ghiso J Frangione B Stern A Schmidt AM Armstrong DL Arnold B Liliensiek B Nawroth P Hofman F Kindy M Stern D Zlokovic B 《Nature medicine》2003,9(7):907-913
Amyloid-beta peptide (Abeta) interacts with the vasculature to influence Abeta levels in the brain and cerebral blood flow, providing a means of amplifying the Abeta-induced cellular stress underlying neuronal dysfunction and dementia. Systemic Abeta infusion and studies in genetically manipulated mice show that Abeta interaction with receptor for advanced glycation end products (RAGE)-bearing cells in the vessel wall results in transport of Abeta across the blood-brain barrier (BBB) and expression of proinflammatory cytokines and endothelin-1 (ET-1), the latter mediating Abeta-induced vasoconstriction. Inhibition of RAGE-ligand interaction suppresses accumulation of Abeta in brain parenchyma in a mouse transgenic model. These findings suggest that vascular RAGE is a target for inhibiting pathogenic consequences of Abeta-vascular interactions, including development of cerebral amyloidosis. 相似文献
966.
967.
Screening for content--the evolution of high throughput 总被引:4,自引:0,他引:4
Dove A 《Nature biotechnology》2003,21(8):859-864
968.
969.
970.
We describe the occurrence of special kinds of hyphae that create anastomoses directly between conidia. They can be found both in the laboratory and on infected plants. They first appear within asexual fruiting bodies approximately 15 days after conidiation has begun leading to the appearance of chains of connected conidia. Coincident with this we demonstrate in Colletotrichum lindemuthianum nuclear dynamics, including fragmentation, with cytoplasmic flow and passage of nuclei and organelles between conidia through the anastomosis tubes. We propose that conidial anastomosis tubes play an important role in the life cycle of these fungi. 相似文献