Fas apoptotic inhibitory molecule 3 (FAIM3; TOSO)

Rabbit serum, preheated at 66 °C for 30 min, produced a stimulation of the incorporation of [3H]uridine by cultured autologous lymph-node cells similar to that caused by concanavalin A (Con-A). However, whereas the percentage stimulation by Con-A increased with time, that by serum preheated at 66 °C (66 °C-serum) reached a peak after 3–4 h and then declined. The decline was greater at higher cell concentrations. Isotope-dilution studies showed that stimulation at 3 h by 66 °C-serum or by Con-A reflected an increase in the maximum velocity of the rate-limiting step for incorporation of [3H]uridine and not a decrease in the pool of uridine and (or) uridine competitors. Experiments in which serum concentration and the relative proportions of serum preheated at 66 °C and serum preheated at 37 °C were varied, suggested that preheating serum at 66 °C removes an inhibitory factor and exposes a stimulatory factor. The stimulatory activity of 66 °C-serum was not dialysable. The results are compatible with a model which requires that lectins activate cultured lymphocytes by influencing the distribution of an inhibitory molecule (perhaps α2-macroglobulin) between the cell surface and the culture medium.

Download Full-text

Conservation of transcriptional activation functions of the NF-kappa B p50 and p65 subunits in mammalian cells and Saccharomyces cerevisiae.

Molecular and Cellular Biology ◽

10.1128/mcb.13.3.1666 ◽

1993 ◽

Vol 13 (3) ◽

pp. 1666-1674 ◽

Cited By ~ 55

Author(s):

P A Moore ◽

S M Ruben ◽

C A Rosen

Keyword(s):

Saccharomyces Cerevisiae ◽

Transcriptional Activation ◽

Mammalian Cells ◽

Transcriptional Activity ◽

Transcriptional Activator ◽

Genetic System ◽

Nf Kappa B ◽

Yeast Saccharomyces Cerevisiae ◽

Activation Domains ◽

Inhibitory Molecule

The NF-kappa B transcription factor complex is composed of a 50-kDa (p50) and a 65-kDa (p65) subunit. Both subunits bind to similar DNA motifs and elicit transcriptional activation as either homo- or heterodimers. By using chimeric proteins that contain the DNA binding domain of the yeast transcriptional activator GAL4 and subdomains of p65, three distinct transcriptional activation domains were identified. One domain was localized to a region of 42 amino acids containing a potential leucin zipper structure, consistent with earlier reports. Two other domains, both acidic and rich in prolines, were also identified. Of perhaps more significance, the same minimal activation domains that were functional in mammalian cells were also functional in the yeast Saccharomyces cerevisiae. Coexpression of the NF-kappa B inhibitory molecule, I kappa B, reduced the transcriptional activity of p65 significantly, suggesting the ability of I kappa B to function in a similar manner in S. cerevisiae. Surprisingly, while the conserved rel homology domain of p65 demonstrated no transcriptional activity in either mammalian cells or S. cerevisiae, the corresponding domain in p50 was a strong transcriptional activator in S. cerevisiae. The observation that similar domains elicit transcriptional activation in mammalian cells and S. cerevisiae demonstrates strong conservation of the transcriptional machinery required for NF-kappa B function and provides a powerful genetic system to study the transcriptional mechanisms of these proteins.

Download Full-text

Fused protein of δPKC activation loop and PDK1-interacting fragment (δAL-PIF) functions as a pseudosubstrate and an inhibitory molecule for PDK1 when expressed in cells

Genes to Cells ◽

10.1111/j.1365-2443.2006.01003.x ◽

2006 ◽

Vol 11 (9) ◽

pp. 1051-1070 ◽

Cited By ~ 5

Author(s):

Takahiro Seki ◽

Naoki Irie ◽

Kyoko Nakamura ◽

Hiroshi Sakaue ◽

Wataru Ogawa ◽

...

Keyword(s):

Activation Loop ◽

Inhibitory Molecule ◽

In Cells

Download Full-text

Axonal growth on astrocytes is not inhibited by oligodendrocytes

Journal of Cell Science ◽

10.1242/jcs.103.2.571 ◽

1992 ◽

Vol 103 (2) ◽

pp. 571-579

Author(s):

J.W. Fawcett ◽

N. Fersht ◽

L. Housden ◽

M. Schachner ◽

P. Pesheva

Keyword(s):

Dorsal Root ◽

Close Contact ◽

Axon Growth ◽

Cell Types ◽

Neonatal Rat ◽

Culture Dish ◽

Inhibitory Molecule ◽

Rat Forebrain ◽

Scanning Electron

Axon growth in vitro may be inhibited by contact with oligodendrocytes, but most axons grow readily on the surface of astrocyte monolayers. Since both cell types are in close contact with one another in the damaged nervous system, we have examined the growth of axons on cultures which contain both astrocytes and oligodendrocytes. Cultures derived from neonatal rat forebrain develop with a monolayer of large flat astrocytes attached to the culture dish, and with many smaller cells of the oligodendrocyte lineage on their surface. Dorsal root ganglia placed on these cultures grow axons readily, the overall extent of growth being unaffected by the presence or absence of oligodendrocytes, many of which express galactocerebroside and the inhibitory molecule janusin. A previous set of experiments had shown that growth of these axons is inhibited by oligodendrocytes by themselves. Scanning electron microscopy coupled with silver-intensified immunostaining reveals that the axons grow on the surface of the astrocytic layer, underneath the oligodendrocytes, and are therefore in contact with both cell types as they grow. The presence of astrocytes therefore alters the results of axonal contact with oligodendrocytes.

Download Full-text

Varespladib Inhibits the Phospholipase A2 and Coagulopathic Activities of Venom Components from Hemotoxic Snakes

Biomedicines ◽

10.3390/biomedicines8060165 ◽

2020 ◽

Vol 8 (6) ◽

pp. 165 ◽

Cited By ~ 2

Author(s):

Chunfang Xie ◽

Laura-Oana Albulescu ◽

Kristina B. M. Still ◽

Julien Slagboom ◽

Yumei Zhao ◽

...

Keyword(s):

Phospholipase A2 ◽

Snake Venom ◽

Snake Venoms ◽

Venom Toxins ◽

Inhibitory Molecule ◽

Coagulation Assay ◽

Potential Clinical Utility ◽

Bothrops Asper ◽

Echis Carinatus ◽

Deinagkistrodon Acutus

Phospholipase A2 (PLA2) enzymes are important toxins found in many snake venoms, and they can exhibit a variety of toxic activities including causing hemolysis and/or anticoagulation. In this study, the inhibiting effects of the small molecule PLA2 inhibitor varespladib on snake venom PLA2s was investigated by nanofractionation analytics, which combined chromatography, mass spectrometry (MS), and bioassays. The venoms of the medically important snake species Bothrops asper, Calloselasma rhodostoma, Deinagkistrodon acutus, Daboia russelii, Echis carinatus, Echis ocellatus, and Oxyuranus scutellatus were separated by liquid chromatography (LC) followed by nanofractionation and interrogation of the fractions by a coagulation assay and a PLA2 assay. Next, we assessed the ability of varespladib to inhibit the activity of enzymatic PLA2s and the coagulopathic toxicities induced by fractionated snake venom toxins, and identified these bioactive venom toxins and those inhibited by varespladib by using parallel recorded LC-MS data and proteomics analysis. We demonstrated here that varespladib was not only capable of inhibiting the PLA2 activities of hemotoxic snake venoms, but can also effectively neutralize the coagulopathic toxicities (most profoundly anticoagulation) induced by venom toxins. While varespladib effectively inhibited PLA2 toxins responsible for anticoagulant effects, we also found some evidence that this inhibitory molecule can partially abrogate procoagulant venom effects caused by different toxin families. These findings further emphasize the potential clinical utility of varespladib in mitigating the toxic effects of certain snakebites.

Download Full-text