1,735 research outputs found
CARMIL family proteins as multidomain regulators of actin-based motility
CARMILs are large multidomain proteins that regulate the actin-binding activity of capping protein (CP), a major capper of actin filament barbed ends in cells. CARMILs bind directly to CP and induce a conformational change that allosterically decreases but does not abolish its actin-capping activity. The CP-binding domain of CARMIL consists of the CP-interaction (CPI) and CARMIL-specific interaction (CSI) motifs, which are arranged in tandem. Many cellular functions of CARMILs require the interaction with CP; however, a more surprising result is that the cellular function of CP in cells appears to require binding to a CARMIL or another protein with a CPI motif, suggesting that CPI-motif proteins target CP and modulate its actin-capping activity. Vertebrates have three highly conserved genes and expressed isoforms of CARMIL with distinct and overlapping localizations and functions in cells. Various domains of these CARMIL isoforms interact with plasma membranes, vimentin intermediate filaments, SH3-containing class I myosins, the dual-GEF Trio, and other adaptors and signaling molecules. These biochemical properties suggest that CARMILs play a variety of membrane-associated functions related to actin assembly and signaling. CARMIL mutations and variants have been implicated in several human diseases. We focus on roles for CARMILs in signaling in addition to their function as regulators of CP and actin. </jats:p
Recommended from our members
B70/B7-2 is identical to CD86 and is the major functional ligand for CD28 expressed on human dendritic cells.
Dendritic cells comprise a system of highly efficient antigen-presenting cells involved in the initiation of T cell responses. Herein, we investigated the role of the CD28 pathway during alloreactive T cell proliferation induced by dendritic-Langerhans cells (D-Lc) generated by culturing human cord blood CD34+ progenitor cells with granulocyte/macrophage colony-stimulating factor and tumor necrosis factor alpha. In addition to expressing CD80 (B7/BB1), a subset of D-Lc expressed B70/B7-2. Binding of the CTLA4-Ig fusion protein was completely inhibited by a combination of monoclonal antibodies (mAbs) against CD80 and B70/B7-2, indicating the absence of expression of a third ligand for CD28/CTLA-4. It is interesting to note that mAbs against CD86 completely prevented the binding of CTLA4-Ig in the presence of mAbs against CD80 and bound to a B70/B7-2-transfected fibroblast cell line, demonstrating that the B70/B7-2 antigen is identical to CD86. CD28 triggering was essential during D-Lc-induced alloreaction as it was inhibited by mAbs against CD28 (9 out of 11 tested). However, none of six anti-CD80 mAbs demonstrated any activity on the D-Lc-induced alloreaction, though some were previously described as inhibitory in assays using CD80-transfected cell lines. In contrast, a mAb against CD86 (IT-2) was found to suppress the D-Lc-dependent alloreaction by 70%. This inhibitory effect was enhanced to > or = 90% when a combination of anti-CD80 and anti-CD86 mAbs was used. The present results demonstrate that D-Lc express, in addition to CD80, the other ligand for CTLA-4, CD86 (B70/B7-2), which plays a primordial role during D-Lc-induced alloreaction
Resistive flow in a weakly interacting Bose-Einstein condensate
We report the direct observation of resistive flow through a weak link in a
weakly interacting atomic Bose-Einstein condensate. Two weak links separate our
ring-shaped superfluid atomtronic circuit into two distinct regions, a source
and a drain. Motion of these weak links allows for creation of controlled flow
between the source and the drain. At a critical value of the weak link
velocity, we observe a transition from superfluid flow to superfluid plus
resistive flow. Working in the hydrodynamic limit, we observe a conductivity
that is 4 orders of magnitude larger than previously reported conductivities
for a Bose-Einstein condensate with a tunnel junction. Good agreement with
zero-temperature Gross-Pitaevskii simulations and a phenomenological model
based on phase slips indicate that the creation of excitations plays an
important role in the resulting conductivity. Our measurements of resistive
flow elucidate the microscopic origin of the dissipation and pave the way for
more complex atomtronic devices.Comment: Version published in PR
A Comparative Analysis of Human Trafficking: The United States of America (USA) and the Republic of South Africa (RSA)
Human trafficking is a serious global problem that transcends international borders and disciplinary boundaries. It presents a conglomeration of problems generally dealt with by public health, criminal justice, social service and immigration agencies. Victim advocates state that millions are victimized each year. The data suggest that law enforcement agencies perceive human trafficking to be of greater, or equal, concern for the myriad of social institutions and participants affected by human trafficking than for law enforcement, itself. Policy recommendations are to refocus the law enforcement response - which may include various approaches that can simultaneously benefit public health - by incorporating an Epidemiological Criminology framework to help to guide the development of more systematic and integrative insight into the world of human trafficking
Recommended from our members
Hypoimmunogenic Derivatives of Induced Pluripotent Stem Cells Evade Immune Rejection in Fully Immunocompetent Allogeneic Recipients
Atomic-scale structure of the SrTiO3(001)-c(6x2) reconstruction: Experiments and first-principles calculations
The c(6x2) is a reconstruction of the SrTiO3(001) surface that is formed
between 1050-1100oC in oxidizing annealing conditions. This work proposes a
model for the atomic structure for the c(6x2) obtained through a combination of
results from transmission electron diffraction, surface x-ray diffraction,
direct methods analysis, computational combinational screening, and density
functional theory. As it is formed at high temperatures, the surface is complex
and can be described as a short-range ordered phase featuring microscopic
domains composed of four main structural motifs. Additionally, non-periodic
TiO2 units are present on the surface. Simulated scanning tunneling microscopy
images based on the electronic structure calculations are consistent with
experimental images
A Surface Reconstruction with a Fractional Hole: LaAlO (001)
The structure of the reconstruction of
LaAlO (001) has been determined using transmission electron diffraction
combined with direct methods. The structure is relatively simple, consisting of
a lanthanum oxide termination with one lanthanum cation vacancy per surface
unit cell. The electronic structure is unusual since a fractional number of
holes or atomic occupancies per surface unit cell are required to achieve
charge neutrality. Density functional calculations indicate that the charge
compensation mechanism occurs by means of highly delocalized holes. The surface
contains no oxygen vacancies and with a better than 99% confidence level, the
holes are not filled with hydrogen. The reconstruction can be understood in
terms of expulsion of the more electropositive cation from the surface followed
by an increased covalency between the remaining surface lanthanum atoms and
adjacent oxygen atoms.Comment: 4 Pages, 3 Figure
- …