Abstract:
:We report here the identification of a pollen-specific gene from Zea mays that contains multiple Ser-(Pro)n repeats, the motif found in the cell wall-associated extensins. Sequence analysis reveals that the encoded protein has a putative globular domain at the N terminus and an extensin-like domain at the C terminus. The Pex1 (pollen extensin-like) gene is expressed exclusively in pollen, not in vegetative or female tissues, and is not induced in leaves upon wounding. We propose that the encoded protein may have a role in reproduction, either as a structural element deposited in the pollen tube wall during its rapid growth or as a sexual recognition molecule that interacts with partner molecules in the pistil.
journal_name
Proc Natl Acad Sci U S Aauthors
Rubinstein AL,Broadwater AH,Lowrey KB,Bedinger PAdoi
10.1073/pnas.92.8.3086subject
Has Abstractpub_date
1995-04-11 00:00:00pages
3086-90issue
8eissn
0027-8424issn
1091-6490journal_volume
92pub_type
杂志文章abstract::How pathogenic cluster of differentiation 4 (CD4) T cells in rheumatoid arthritis (RA) develop remains poorly understood. We used Nur77-a marker of T cell antigen receptor (TCR) signaling-to identify antigen-activated CD4 T cells in the SKG mouse model of autoimmune arthritis and in patients with RA. Using a fluoresce...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1904271116
更新日期:2019-09-10 00:00:00
abstract::Fibrocytes are collagen-type-I-producing cells that arise at low frequency from hematopoietic cells. We have analyzed in mice which leukocyte subsets are required for generation of fibrocytes and show that murine fibrocytes develop from the subpopulation of CD11b(+) CD115(+) Gr1(+) monocytes under the control of CD4(+...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0906070106
更新日期:2009-10-20 00:00:00
abstract::We measured the superconducting transition temperature of (6)Li between 16 and 26 GPa, and report the lightest system to exhibit superconductivity to date. The superconducting phase diagram of (6)Li is compared with that of (7)Li through simultaneous measurement in a diamond anvil cell (DAC). Below 21 GPa, Li exhibits...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1412638112
更新日期:2015-01-06 00:00:00
abstract::Immunoaffinity-purified interleukin 2 (IL2) stimulated proliferation of large but not small B cells. Stimulation was observed even when B cells were cultured at very low cell densities (3 X 10(4) per microwell containing 0.2 ml of medium). Addition of small numbers of purified splenic T cells did not enhance the IL2-i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.5.1518
更新日期:1985-03-01 00:00:00
abstract::The Cdc28 protein kinase functions in the G1 to S phase transition of the cell cycle of the budding yeast Saccharomyces cerevisiae. This is in contrast with observations of the homologous protein kinase from a variety of metazoans, where activity and function are associated with the G2 to M phase transition. We presen...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.15.5697
更新日期:1990-08-01 00:00:00
abstract::We address the stability of multicharged finite systems driven by Coulomb forces beyond the Rayleigh instability limit. Our exploration of the nuclear dynamics of heavily charged Morse clusters enabled us to vary the range of the pair potential and of the fissibility parameter, which results in distinct fragmentation ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.142253999
更新日期:2002-07-09 00:00:00
abstract::CD11c, also known as integrin alpha X, is the most widely used defining marker for dendritic cells (DCs). CD11c can bind complement iC3b and mediate phagocytosis in vitro, for which it is also referred to as complement receptor 4. However, the functions of this prominent marker protein in DCs, especially in vivo, rema...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1805542115
更新日期:2018-06-26 00:00:00
abstract::The lymphoma-inducing potential of Ig heavy-chain enhancer- and promoter-regulated Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) was evaluated in three transgenic FVB mouse lineages. EBNA1 was expressed at a higher level in transgenic B220(+) splenocytes than in EBV-infected lymphoblastoid cell lines. EBNA1 was a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0408774102
更新日期:2005-01-18 00:00:00
abstract::Phosphatidylinositol 3,4,5-triphosphate (PIP3) plays a key role in neuronal polarization and axon formation. PIP3-containing vesicles are transported to axon tips by the kinesin KIF13B via an adaptor protein, centaurin α1 (CENTA1). KIF13B interacts with CENTA1 through its forkhead-associated (FHA) domain. We solved th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1009008107
更新日期:2010-11-23 00:00:00
abstract::The first crystal structure of the neurotransmitter/sodium symporter homolog LeuT revealed an occluded binding pocket containing leucine and 2 Na(+); later structures showed tricyclic antidepressants (TCAs) in an extracellular vestibule approximately 11 A above the bound leucine and 2 Na(+). We recently found this reg...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0811322106
更新日期:2009-04-07 00:00:00
abstract::Recent reports on the dystrophic mouse mutant suggest that the prominent extracellular matrix component of peripheral nerve tissues plays an important role in peripheral nerve development. We have examined the disposition of two prominent extracellular matrix components, fibronectin and laminin, both in mature periphe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.12.3850
更新日期:1983-06-01 00:00:00
abstract::Pathogenetic processes that facilitate the entry, replication, and persistence of Mycobacterium tuberculosis (MTB) in the mammalian host likely include the regulated expression of specific sets of genes at different stages of infection. Identification of genes that are differentially expressed in vivo would provide in...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2436197100
更新日期:2003-11-25 00:00:00
abstract::Type I interferons (IFNs) are helical cytokines that have diverse biological activities despite the fact that they appear to interact with the same receptor system. To achieve a better understanding of the structural basis for the different activities of alpha and beta IFNs, we have determined the crystal structure of...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.22.11813
更新日期:1997-10-28 00:00:00
abstract::Many substances in the plant kingdom and in man's diet occur as glycosides. Recent studies have indicated that many glycosides that are not mutagenic in tests such as the Salmonella test become mutagenic upon hydrolysis of the glycosidic linkages. The Salmonella test utilizes a liver homogenate to approximate mammalia...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.8.4961
更新日期:1980-08-01 00:00:00
abstract::The endogenous cannabinoid anandamide is removed from the synaptic space by a high-affinity transport system present in neurons and astrocytes, which is inhibited by N-(4-hydroxyphenyl)-arachidonamide (AM404). After internalization, anandamide is hydrolyzed by fatty-acid amide hydrolase (FAAH), an intracellular membra...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0400997101
更新日期:2004-06-08 00:00:00
abstract::A nitrogenase-inspired biomimetic chalcogel system comprising double-cubane [Mo2Fe6S8(SPh)3] and single-cubane (Fe4S4) biomimetic clusters demonstrates photocatalytic N2 fixation and conversion to NH3 in ambient temperature and pressure conditions. Replacing the Fe4S4 clusters in this system with other inert ions such...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1605512113
更新日期:2016-05-17 00:00:00
abstract::Identifying causal effects in nonexperimental data is an enduring challenge. One proposed solution that recently gained popularity is the idea to use genes as instrumental variables [i.e., Mendelian randomization (MR)]. However, this approach is problematic because many variables of interest are genetically correlated...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1707388115
更新日期:2018-05-29 00:00:00
abstract::Cloned 3.18 kilobase fragments of Xenopus laevis DNA containing genes for tRNAMet1 and for at least one other 4S RNA species are transcribed rapidly after their injection into the nucleus of X. laevis oocytes. The newly synthesized RNA can be resolved by gel electrophoresis into a few predominant 4S RNA species and a ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.3.1176
更新日期:1978-03-01 00:00:00
abstract::We have initiated immunological and drug-binding studies on the tubulins from different higher plant species. Antibodies were raised against electrophoretically separated rose (Rosa sp.) tubulin alpha- and beta-subunits and characterized by immunoblot autoradiographic assays. Each IgG preparation bound to its antigen ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.5.1440
更新日期:1984-03-01 00:00:00
abstract::Single molecule atomic force microscopy was used to characterize structure, binding strength (unbinding force), and binding kinetics of a classical cadherin, vascular endothelial (VE)-cadherin, secreted by transfected Chinese hamster ovary cells as cis-dimerized full-length external domain fused to Fc-portion of human...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.070052697
更新日期:2000-04-11 00:00:00
abstract::Studies of phage lambda in vivo have indicated that its own recombination enzymes, beta protein and lambda exonuclease, are capable of catalyzing two dissimilar pathways of homologous recombination that are widely distributed in nature: single-strand annealing and strand invasion. The former is an enzymatic splicing o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0408046101
更新日期:2004-12-07 00:00:00
abstract::The past two decades have seen an enormous growth in the field of human brain mapping. Investigators have extensively exploited techniques such as positron emission tomography and MRI to map patterns of brain activity based on changes in cerebral hemodynamics. However, until recently, most studies have investigated eq...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.95.3.773
更新日期:1998-02-03 00:00:00
abstract::MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity. Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers. The high aspect ratio of delaminated MXene renders it promising nanofiller in multifunc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1414215111
更新日期:2014-11-25 00:00:00
abstract::Epithelial cells are organized into either a single layer (simple epithelia) or multiple layers (stratified epithelia). Maintenance of these cellular organizations requires distinct adhesive mechanisms involving many cell surface molecules. One such molecule is a cell surface proteoglycan, named syndecan, that contain...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.24.9562
更新日期:1988-12-01 00:00:00
abstract::The phosphoinositide 3-kinase (PI3K) pathway is central to the metabolic actions of insulin on liver. Here, we show that mice with a liver-specific deletion of the p85alpha regulatory subunit of PI3K (L-Pik3r1KO) exhibit a paradoxical improvement of hepatic and peripheral insulin sensitivity. Although PI3K enzymatic a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0604628103
更新日期:2006-08-08 00:00:00
abstract::In vivo electroporation is a powerful technique for the introduction of genes into organisms. Temporal and spatial regulation of expression of introduced genes, or of RNAi, would further enhance the utility of this method. Here we demonstrate conditional regulation of gene expression from electroporated plasmids in th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0610155104
更新日期:2007-01-16 00:00:00
abstract::Protein homeostasis is critically important for cell viability. Key to this process is the refolding of misfolded or aggregated proteins by molecular chaperones or, alternatively, their degradation by proteases. In most prokaryotes and in chloroplasts and mitochondria, protein degradation is performed by the caseinoly...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1805125115
更新日期:2018-07-10 00:00:00
abstract::In nine patients with GM1 gangliosidosis, liver ganglioside GM1 beta-galactosidase (EC 3.2.1.23) activity ranged from less than 0.01% to 0.05% of normal. In a tenth patient's liver, much higher activity was found (0.5% of normal). In this patient the residual enzyme had the same molecular weight as beta-galactosidase ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.1.240
更新日期:1975-01-01 00:00:00
abstract::The Fas/APO-1 cytotoxic pathway plays an important role in the regulation of peripheral immunity. Recent evidence indicates that this regulatory function operates through deletion of activated T and B lymphocytes by CD4+ T cells expressing the Fas ligand. Because macrophages play a key role in peripheral immunity, we ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.24.11225
更新日期:1995-11-21 00:00:00
abstract::Realizing the goal of the Paris Agreement to limit global warming to 2 °C by the end of this century will most likely require deployment of carbon-negative technologies. It is particularly important that China, as the world's top carbon emitter, avoids being locked into carbon-intensive, coal-fired power-generation te...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1812239116
更新日期:2019-04-23 00:00:00