The cohesion protein ORD is required for homologue bias during meiotic recombination.
AuthorsWebber HA, Howard L, Bickel SE
JournalJ Cell Biol
PubMed ID15007062
'During meiosis, sister chromatid cohesion is required for normal levels of homologous recombination, although how cohesion regulates exchange is not understood. Null mutations in orientation disruptor (ord) ablate arm and centromeric cohesion during Drosophila meiosis and severely reduce homologous crossovers in mutant oocytes. We show that ORD protein localizes along ... More
Exocytosis of IgG as mediated by the receptor, FcRn: an analysis at the single-molecule level.
AuthorsOber RJ, Martinez C, Lai X, Zhou J, Ward ES
JournalProc Natl Acad Sci U S A
PubMed ID15258288
'IgG transport within and across cells is essential for effective humoral immunity. Through a combination of biochemical and in vivo analyses, the MHC class I-related neonatal Fc receptor (FcRn) is known to play a central role in delivering IgGs within and across cells. However, little is known about the molecular ... More
Colocalization of fluorescent markers in confocal microscope images of plant cells.
'This protocol describes the steps needed to perform quantitative statistical colocalization on two-color confocal images, specifically of plant cells. The procedure includes a calibration test to check the chromatic alignment of the confocal microscope. A software tool is provided to calculate the Pearson and Spearman correlation coefficients (''Pearson-Spearman correlation colocalization'' ... More
AuthorsPuri N, Kruhlak MJ, Whiteheart SW, Roche PA
JournalJ Immunol
PubMed ID14607937
'Mast cells possess specialized granules that, upon stimulation of surface FcR with IgE, fuse with the plasma membrane, thereby releasing inflammatory mediators. A family of membrane fusion proteins called SNAREs, which are present on both the granule and the plasma membrane, plays a role in the fusion of these granules ... More
Three-dimensional random access multiphoton microscopy for functional imaging of neuronal activity.
The dynamic ability of neuronal dendrites to shape and integrate synaptic responses is the hallmark of information processing in the brain. Effectively studying this phenomenon requires concurrent measurements at multiple sites on live neurons. Substantial progress has been made by optical imaging systems that combine confocal and multiphoton microscopy with ... More
Cytogenetic evidence for asexual evolution of bdelloid rotifers.
AuthorsMark Welch JL, Mark Welch DB, Meselson M
JournalProc Natl Acad Sci U S A
PubMed ID14747655
DNA sequencing has shown individual bdelloid rotifer genomes to contain two or more diverged copies of every gene examined and has revealed no closely similar copies. These and other findings are consistent with long-term asexual evolution of bdelloids. It is not entirely ruled out, however, that bdelloid genomes consist of ... More
The mitotic DNA damage checkpoint proteins Rad17 and Rad24 are required for repair of double-strand breaks during meiosis in yeast.
AuthorsShinohara M, Sakai K, Ogawa T, Shinohara A
JournalGenetics
PubMed ID12871899
We show here that deletion of the DNA damage checkpoint genes RAD17 and RAD24 in Saccharomyces cerevisiae delays repair of meiotic double-strand breaks (DSBs) and results in an altered ratio of crossover-to-noncrossover products. These mutations also decrease the colocalization of immunostaining foci of the RecA homologs Rad51 and Dmc1 and ... More
Disruption of cytoskeletal integrity impairs Gi-mediated signaling due to displacement of Gi proteins.
AuthorsBloch W, Fan Y, Han J, Xue S, Schöneberg T, Ji G, Lu ZJ, Walther M, Fässler R, Hescheler J, Addicks K, Fleischmann BK
JournalJ Cell Biol
PubMed ID11514589
beta1 integrins play a crucial role as cytoskeletal anchorage proteins. In this study, the coupling of the cytoskeleton and intracellular signaling pathways was investigated in beta1 integrin deficient (-/-) embryonic stem cells. Muscarinic inhibition of the L-type Ca2+ current (ICa) and activation of the acetylcholine-activated K+ current (IK,ACh) was found ... More
Determinants of liposome fusion mediated by synaptic SNARE proteins.
AuthorsSchuette CG, Hatsuzawa K, Margittai M, Stein A, Riedel D, Küster P, König M, Seidel C, Jahn R
JournalProc Natl Acad Sci U S A
PubMed ID14981239
Synaptic exocytosis requires the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins syntaxin 1, SNAP-25, and synaptobrevin (VAMP). Assembly of the SNAREs into a stable core complex is supposed to catalyze membrane fusion, and proteoliposomes reconstituted with synaptic SNARE proteins spontaneously fuse with each other. We now show that liposome ... More
The Saccharomyces cerevisiae spindle pole body is a dynamic structure.
AuthorsYoder TJ, Pearson CG, Bloom K, Davis TN
JournalMol Biol Cell
PubMed ID12925780
During spindle pole body (SPB) duplication, the new SPB is assembled at a distinct site adjacent to the old SPB. Using quantitative fluorescence methods, we studied the assembly and dynamics of the core structural SPB component Spc110p. The SPB core exhibits both exchange and growth in a cell cycle-dependent manner. ... More
Epitope-dependent localization of estrogen receptor-alpha, but not -beta, in en face arterial endothelium.
AuthorsDan P, Cheung JC, Scriven DR, Moore ED
JournalAm J Physiol Heart Circ Physiol
PubMed ID12531733
Rapid, nongenomic effects of 17 beta-estradiol (E(2)) in endothelial cells are postulated to arise from membrane-associated estrogen receptors (ERs), which have not been visualized in vascular tissue. To identify membrane ERs, we used multiple site-directed ER alpha or ER beta antibodies to label en face rat cerebral and coronary arterial ... More
Meiotic cohesion requires accumulation of ORD on chromosomes before condensation.
AuthorsBalicky EM, Endres MW, Lai C, Bickel SE
JournalMol Biol Cell
PubMed ID12429833
Cohesion between sister chromatids is a prerequisite for accurate chromosome segregation during mitosis and meiosis. To allow chromosome condensation during prophase, the connections that hold sister chromatids together must be maintained but still permit extensive chromatin compaction. In Drosophila, null mutations in the orientation disruptor (ord) gene lead to meiotic ... More
Site of docking and fusion of insulin secretory granules in live MIN6 beta cells analyzed by TAT-conjugated anti-syntaxin 1 antibody and total internal reflection fluorescence microscopy.
AuthorsOhara-Imaizumi M, Nishiwaki C, Kikuta T, Kumakura K, Nakamichi Y, Nagamatsu S
JournalJ Biol Chem
PubMed ID14676208
To determine the site of insulin exocytosis in the pancreatic beta cell plasma membrane, we analyzed the interaction between the docking/fusion of green fluorescent protein-tagged insulin granules and syntaxin 1 labeled by TAT-conjugated Cy3-labeled antibody (Ab) using total internal reflection fluorescence microscopy (TIRFM). Monoclonal Ab against syntaxin 1 was labeled ... More
Recruitment of 7SL RNA to assembling HIV-1 virus-like particles.
AuthorsItano MS, Arnion H, Wolin SL, Simon SM
JournalTraffic
PubMed ID29044909
'Retroviruses incorporate specific host cell RNAs into virions. In particular, the host noncoding 7SL RNA is highly abundant in all examined retroviruses compared with its cellular levels or relative to common mRNAs such as actin. Using live cell imaging techniques, we have determined that the 7SL RNA does not arrive ... More
Amyloid oligomerization of the Parkinson's disease related protein a-synuclein impacts on its curvature-membrane sensitivity.
AuthorsGallea JI, Ambroggio EE, Vilcaes AA, James NG, Jameson DM, Celej MS
JournalJ Neurochem
PubMed ID30142705
'The amyloid aggregation of the presynaptic protein a-synuclein (AS) is pathognomonic of Parkinson''s disease and other neurodegenerative disorders. Physiologically, AS contributes to synaptic homeostasis by participating in vesicle maintenance, trafficking, and release. Its avidity for highly curved acidic membranes has been related to the distinct chemistry of the N-terminal amphipathic ... More
Using the NoiSee workflow to measure signal-to-noise ratios of confocal microscopes.
AuthorsFerrand A, Schleicher KD, Ehrenfeuchter N, Heusermann W, Biehlmaier O
JournalSci Rep
PubMed ID30718583
Confocal microscopy is used today on a daily basis in life science labs. This "routine" technique contributes to the progress of scientific projects across many fields by revealing structural details and molecular localization, but researchers need to be aware that detection efficiency and emission light path performance is of major ... More