The effects of maturation on self-induced dynamic body sway frequencies of girls performing acrobatics or classical dance

We investigated the effects of maturation on the dynamic body sways of healthy girls. Prepubertal and postpubertal girls practising professional physical activities requiring a good ability to maintain equilibrium (acrobats and dancers) were asked to stand on a free seesaw platform and the results compared to those for untrained age-matched girls. This platform (stabilometer) allows self-induced body sways. Stabilograms were obtained by a double integration of the angular acceleration from the recordings of the platform sways made with an accelerometer. Fast Fourier transform processing of stabilograms allowed spectral frequency analysis. The total spectrum energy and the energies of three frequency bands (0–0.5 Hz, 0.5–2 Hz, 2–20 Hz) were determined. ANOVA showed that, for all groups of different equilibrium activity and independent of visual input, prepubertal girls had higher energy values than postpubertal girls in the 0- to 0.5-Hz band whereas the opposite was true for 0.5- to 2-Hz band. Ballet dancers were more dependent than acrobats on visual inputs for the regulation of their postural control but were less dependent than untrained girls at both ages. Maturation seemed to shift body sways towards higher frequencies and the utilization of the cues of postural control was different according to the type of equilibrium activity practised by the subjects. Accepted: 7 February 1997     

Purification and Characterization of a Human Brain Galectin-1 Ligand

Abstract: Our previous studies have characterized an endogenous lectin from human brain identified as galectin-1. A soluble ligand of galectin-1 was purified from human brain by affinity chromatography and preparative electrophoresis. The purified ligand (termed HBGp82, for human brain galectin-1-binding polypeptide of 82,000 daltons) has an apparent molecular mass of 82 kDa and is glycosylated by N -linked biantennary complex structures. HBGp82 was partially characterized by microsequencing of peptide fragments. Similar peptides were found in a heat shock of protein of 90,000 daltons, hsp90. However, comparison of apparent molecular weights and matrix-assisted laser desorption mass spectrometry clearly showed that HBGp82 differs to some degree from hsp90.     

Structural changes in bovine oocytes during final maturation in vivo

On the basis of structural observations bovine oocytes were grouped into four successive classed: 0, those before the luteinizing hormone (LH) surge; 1, those up to 8 h following the LH peak level; 2, those between 8 and 19 h after the LH peak level; and 3, those between 19 h after the LH peak level and ovulation. Oocytes in class 0 had mitochondria located in a generally peripheral position. Interior to the mitochondria were elements of rough endoplasmic reticulum (RER) and numerous membrane-bound vesicles which bore ribosome-like particles on their outer surface. The first visible changesater the LH peak level as seen in class 1 were the formation of the periviteline space with loss of contact between the cumulus cells and the oocyte, and ruffing of the nuclear envelope. These changes were followed b the resumption of meiosis as defined by germinal-vesicle breakdown (GVBD), the disappearance of RER, and the formation fo clusters of mitochondria in association with lipid droplets and elementrs of smooth endolasmic reticulum (SER). The period between 8 and 19 h following LH peak level (class 2) was characterized by intensive clustering of mitochoncria in association with lipid droplets and elements of SER, conversion of lipid, fusion of vesicles, and the appearance of ribosomes in the cytoplasm. During the final stage (class 3), the polar body was extruded, the mitochondria dispersed, and the majority of the organelles became located toward the center of the cell. The relatively organelle-free cortical region contained cortical granules immediately adjacent to the plasma membrane together with aggregates of tubular SER. The structural changes are discussed in the context of follicular steroidogenesis and oocyte developmental competence.     

Changes in Electrophoretic Patterns of Oocyte Proteins during Oocyte Maturation in Oryzias latipes

Changes in the two-dimensional SDS-electrophoretic patterns of extracts of maturing denuded oocytes of the medaka ( Oryzias latipes ) were surveyed. In oocytes without follicular constituents several proteins became detectable in the area between the acidic and slightly basic proteins on the two-dimensional electrophoretograms, while a few of the protein spots disappeared during the process of oocyte maturation. The former proteins were detected also in oocytes that were induced to mature in vivo without breakdown of the germinal vesicle. Several proteins newly observed in extracts of post-vitellogenic oocytes during maturation after breakdown of the germinal vesicle were also identified by two-dimensional electrophoresis. Of several proteins that exhibited noticeable changes in maturing oocytes, only one spot incorporated ¹⁴C-labeled amino acid during maturation, suggesting that post-translational modification of many proteins occurred during oocyte maturation.     

Human C1orf27 protein interacts with α2A-adrenergic receptor and regulates its anterograde transport

The molecular mechanisms underlying the anterograde surface transport of G protein–coupled receptors (GPCRs) after their synthesis in the endoplasmic reticulum (ER) are not well defined. In C. elegans, odorant response abnormal 4 has been implicated in the delivery of olfactory GPCRs to the cilia of chemosensory neurons. However, the function and regulation of its human homolog, C1orf27, in GPCR transport or in general membrane trafficking remain unknown. Here, we demonstrate that siRNA-mediated knockdown of C1orf27 markedly impedes the ER-to-Golgi export kinetics of newly synthesized α_2A-adrenergic receptor (α_2A-AR), a prototypic GPCR, with the half-time being prolonged by more than 65%, in mammalian cells in retention using the selective hooks assays. Using modified bioluminescence resonance energy transfer assays and ELISAs, we also show that C1orf27 knockdown significantly inhibits the surface transport of α_2A-AR. Similarly, C1orf27 knockout by CRISPR-Cas9 markedly suppresses the ER–Golgi-surface transport of α_2A-AR. In addition, we demonstrate that C1orf27 depletion attenuates the export of β₂-AR and dopamine D2 receptor but not of epidermal growth factor receptor. We further show that C1orf27 physically associates with α_2A-AR, specifically via its third intracellular loop and C terminus. Taken together, these data demonstrate an important role of C1orf27 in the trafficking of nascent GPCRs from the ER to the cell surface through the Golgi and provide novel insights into the regulation of the biosynthesis and anterograde transport of the GPCR family members.     

The affinity of human RANK binding to its ligand RANKL

Receptor activator of nuclear factor-kappa B (RANK) and its ligand, RANKL play critical roles in bone re-modeling, immune function, vascular disease and mammary gland development. To study the interaction of RANK and RANKL, we have expressed both extracellular domain of RANK and ectodomain of RANKL using Escherichia coli expression system. RANK was expressed as an inclusion body first which properly refolded later, while RANKL was initially produced as a GST fusion protein, after which the GST was removed by enzyme digestion. Soluble RANK existed as a monomer while RANKL was seen as a trimer in solution, demonstrated by gel filtration chromatography and cross-linking experiment. The recombinant RANK and RANKL could bind to each other and the binding affinity of RANKL for RANK was measured with surface plasmon resonance technology and K_D value is about 1.09 × 10⁻¹⁰ M.     

GMF-Knockout Mice are Unable to Induce Brain-Derived Neurotrophic Factor after Exercise

We earlier reported that overexpression of glia maturation factor (GMF) in cultured astrocytes enhances the production of brain-derived neurotrophic factor (BDNF). The current study was conducted to find out whether BDNF production is impaired in animals devoid of GMF. To this end GMF-knockout (KO) mice were subjected to exercise and the neurotrophin mRNAs were determined by real-time RT-PCR. Compared to wild-type (WT) mice, there is a decrease in exercise-induced BDNF in the KO mice. The observation was correlated with the finding that, in WT mice, exercise increases GMF expression. The results are consistent with the hypothesis that GMF is necessary for exercise-induction of BDNF, and that GMF may promote neuroprotection through BDNF production.