Single-particle tracking of quantum dot-conjugated prion proteins inside yeast cells.

Yeast is a model eukaryote with a variety of biological resources. Here we developed a method to track a quantum dot (QD)-conjugated protein in the budding yeast Saccharomyces cerevisiae. We chemically conjugated QDs with the yeast prion Sup35, incorporated them into yeast spheroplasts, and tracked the motions by conventional two-dimensional or three-dimensional tracking microscopy.

Mutation in the RNA binding protein TIS11D/ZFP36L2 is associated with the pathogenesis of acute leukemia.

TIS11D is an AU-rich element binding protein that is involved in RNA metabolism and definitive hematopoiesis. Although disruption of genes related to hematopoiesis often leads to the development of leukemia and lymphoma, the involvement of TIS11D in hematological malignancies remains to be determined. In the present study, we identified a heterozygous frameshift mutation (I373fsX91) in the carboxy-terminus of the TIS11D gene in leukemic cells from a patient with acute myeloid leukemia.

The DM domain transcription factor MAB-3 regulates male hypersensitivity to oxidative stress in Caenorhabditis elegans.

Sex differences occur in most species and involve a variety of biological characteristics. The nematode Caenorhabditis elegans consists of two sexes, self-fertile hermaphrodites (XX) and males (XO). Males differ from hermaphrodites in morphology, behavior, and life span.

Membranous nephropathy after allogeneic stem cell transplantation: report of 2 cases.

Nephrotic syndrome (NS) is a rare complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The cases of 2 patients who developed NS after receiving allo-HSCT for chronic myelogenous leukemia and acute lymphoblastic leukemia are described. In both cases, renal biopsy revealed membranous nephropathy (MN), and the patients achieved remission after treatment with prednisolone.

Combination of AFM with an objective-type total internal reflection fluorescence microscope (TIRFM) for nanomanipulation of single cells.

A new instrument was constructed by combining an objective-type total internal reflection fluorescence microscope with an atomic force microscope (AFM). Our purpose of constructing such an instrument is to detect and confirm the result of cellular level manipulations made with the AFM part through the detection system of the highly sensitive fluorescence microscope part. In this combination, manipulations are now possible from the nanometer to the micrometer scales and the fluorescence detection system is sensitive enough even for localizing single molecules.

Heat shock protein 90 and the nuclear transport of progesterone receptor.

Steroid receptors exist as large oligomeric complexes in hypotonic cell extracts. In the present work, we studied the nuclear transport of the 2 major components of the oligomeric complex, the receptor itself and the heat shock protein 90 (Hsp90), by using different in vitro transport systems: digitonin permeabilized cells and purified nuclei. We demonstrate that the stabilized oligomeric complex of progesterone receptor (PR) cannot be transported into the nucleus and that unliganded PR salt dissociated from Hsp90 is transported into the nucleus.

A nonproteolytic function of the proteasome is required for the dissociation of Cdc2 and cyclin B at the end of M phase.

Inactivation of cyclin B-Cdc2 kinase at the exit from M phase depends on the specific proteolysis of the cyclin B subunit, whereas the Cdc2 subunit remains present at nearly constant levels throughout the cell cycle. It is unknown how Cdc2 escapes degradation when cyclin B is destroyed. In Xenopus egg extracts that reproduce the exit from M phase in vitro, we have found that dissociation of the cyclin B-Cdc2 complex occurred under conditions where cyclin B was tethered to the 26S proteasome but not yet degraded.

Maternal mRNA localization of zebrafish DAZ-like gene.

Members of the DAZ gene family encode RNA-binding proteins and have been shown to play a pivotal role in gametogenesis. In Xenopus, a DAZ-like gene encodes an RNA component of the germ plasm. We have identified a zebrafish DAZ homologue, zDazl.