A novel approach to in situ characterization of pancreatic beta-cells.
AuthorsSpeier S, Rupnik M
JournalPflugers Arch
PubMed ID12774232
'The tissue-slice technique has enabled major insights into neural and neuroendocrine physiology. Our aim was to adapt this technique to study the function of the endocrine pancreas. The preparation combines an in situ approach, as in gland perfusion, with a resolution characteristic of electrophysiological studies on single cells. The membrane ... More
Liver fatty acid-binding protein colocalizes with peroxisome proliferator activated receptor alpha and enhances ligand distribution to nuclei of living cells.
AuthorsHuang H, Starodub O, McIntosh A, Atshaves BP, Woldegiorgis G, Kier AB, Schroeder F
JournalBiochemistry
PubMed ID14992586
'Although it is hypothesized that long-chain fatty acyl CoAs (LCFA-CoAs) and long-chain fatty acids (LCFAs) regulate transcription in the nucleus, little is known regarding factors that determine the distribution of these ligands to nuclei of living cells. Immunofluorescence colocalization showed that liver fatty acid-binding protein (L-FABP; binds LCFA-CoA as well ... More
The endoplasmic reticulum can act as a functional Ca2+ store in all subcellular regions of the pancreatic acinar cell.
Authorsvan de Put FH, Elliott AC
JournalJ Biol Chem
PubMed ID9346920
'Stimulation of pancreatic acinar cells raises [Ca2+]i via Ca2+ release from inositol-1,4,5-trisphosphate (InsP3)-sensitive intracellular Ca2+ stores, generally considered to reside within the endoplasmic reticulum (ER). However, with physiological doses of cholinergic agonists, the [Ca2+]i increase is localized to the apical (secretory) pole of the cell, leading to suggestions that zymogen ... More
Intramitochondrial location and dynamics of Crithidia fasciculata kinetoplast minicircle replication intermediates.
AuthorsDrew ME, Englund PT
JournalJ Cell Biol
PubMed ID11352935
Kinetoplast DNA, the mitochondrial DNA of Crithidia fasciculata, is organized into a network containing 5,000 topologically interlocked minicircles. This network, situated within the mitochondrial matrix, is condensed into a disk-shaped structure located near the basal body of the flagellum. Fluorescence in situ hybridization revealed that before their replication, minicircles are ... 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
Ectopic scute induces Drosophila ommatidia development without R8 founder photoreceptors.
AuthorsSun Y, Jan LY, Jan YN
JournalProc Natl Acad Sci U S A
PubMed ID10823908
During development of the Drosophila peripheral nervous system, different proneural genes encoding basic helix-loop-helix transcription factors are required for different sensory organs to form. atonal (ato) is the proneural gene required for chordotonal organs and R8 photoreceptors, whereas the achaete-scute complex contains proneural genes for external sensory organs such as ... More
The mouse SKD1, a homologue of yeast Vps4p, is required for normal endosomal trafficking and morphology in mammalian cells.
AuthorsYoshimori T, Yamagata F, Yamamoto A, Mizushima N, Kabeya Y, Nara A, Miwako I, Ohashi M, Ohsumi M, Ohsumi Y
JournalMol Biol Cell
PubMed ID10679028
The mouse SKD1 is an AAA-type ATPase homologous to the yeast Vps4p implicated in transport from endosomes to the vacuole. To elucidate a possible role of SKD1 in mammalian endocytosis, we generated a mutant SKD1, harboring a mutation (E235Q) that is equivalent to the dominant negative mutation (E233Q) in Vps4p. ... More
p150Glued, the largest subunit of the dynactin complex, is nonessential in Neurospora but required for nuclear distribution.
AuthorsTinsley JH, Minke PF, Bruno KS, Plamann M
JournalMol Biol Cell
PubMed ID8744947
Dynactin is a multisubunit complex that is required for cytoplasmic dynein, a minus-end-directed, microtubule-associated motor, to efficiently transport vesicles along microtubules in vitro. p150Glued, the largest subunit of dynactin, has been identified in vertebrates and Drosophila and recently has been shown to interact with cytoplasmic dynein intermediate chains in vitro. ... More
Requirement for Ras and phosphatidylinositol 3-kinase signaling uncouples the glucocorticoid-induced junctional organization and transepithelial electrical resistance in mammary tumor cells.
AuthorsWoo PL, Ching D, Guan Y, Firestone GL
JournalJ Biol Chem
PubMed ID10551843
In Con8 rat mammary epithelial tumor cells, the synthetic glucocorticoid dexamethasone stimulates the remodeling of the apical junction (tight and adherens junctions) and the transepithelial electrical resistance (TER), which reflects tight junction sealing. Indirect immunofluorescence revealed that dexamethasone induced the recruitment of endogenous Ras and the p85 regulatory subunit of ... More