Abelson Family Protein Tyrosine Kinases and the Formation of Neuronal Connectivity

The nervous system is an organ of immense complexity. Neural function and the integration of neural input depend upon the formation of an intricate network of synaptic connections. Building this neural architecture during development involves several aspects of neuronal morphogenesis, from neuronal ...

Abl and Cell Death

The Abl tyrosine kinase contains nuclear-import and -export signals and undergoes nucleo-cytoplasmic shuttling in proliferating cells. The nuclear Abl is activated by DNA damage or tumor necrosis factor to promote cell death through transcription-dependent and -independent mechanisms. The oncogenic ...

Abl Family Kinases in Mammalian Development

Abl and Arg nonreceptor tyrosine kinases are widely expressed in mammals, where they contribute to the development of diverse organ and tissue systems. Deletion of abl or arg in mice reveals roles for the kinases in B and T lymphocyte development, neurulation, neuronal dendrite maintenance, synaptic...

Adaptive Responses of Early Embryos to their Microenvironment and Consequences for Post-Implantation Development

Jeremy Thompson*, Michelle Lane and Sarah Robertson

Early embryos are adaptive to the environment they encounter during development and this facilitates embryo resilience to environmental insults. However, it is clear from findings in nonhuman species that adaptive plasticity during early development can have adverse consequences manifesting over ...

Agonists of Toll-Like Receptor 9: Modulation of Host Immune Responses with Synthetic Oligodeoxynucleotides

Ekambar R. Kandimalla and Sudhir Agrawal

Innate immunity is the body’s first line of defense against invading microbes. This component of our immune system relies on highly conserved pattern-recognition receptors (PRRs) to distinguish different pathogens.1 Toll-like receptors (TLRs) are one class of PRR1,2 of which ten (TLR1-10) have no...

Ca²⁺ Regulation of Drosophila Phototransduction

Joseph E. O'Tousa

Drosophila vision research has benefited from simultaneous application of genetic, molecular, electrophysiological analyses. The work establishes an essential role of Ca²⁺ in regulation of phototransduction. Many different proteins are the targets of Ca²⁺ reg...

Ca²⁺-Channels in the RPE

Rita Rosenthal and Olaf Strauß

The retinal pigment epithelium closely interacts with photoreceptors and helps to maintain the activity of photoreceptors. Investigations using patch-clamp techniques on cultured or freshly isolated retinal pigment epithelial cells from various species demonstrated the expression of volt...

Ca²⁺-Dependent Control of Rhodopsin Phosphorylation: Recoverin and Rhodopsin Kinase

I.I.Senin, K.WKoch, M.Akhtar and P.P.Philippov

Over many years until the middle of the 1980s, the main problem in vision research had been the mechanism of transducing the visual signal from photobleached rhodopsin to the cationic channels in the plasma membrane of a photoreceptor to trigger the electrophysiological response of the c...

Calcium and Phototransduction

K. Nakatani, C. Chen, K.W. Yau and Y. Koutalos

Visual phototransduction, the conversion of incoming light to an electrical signal, takes place in the outer segments of the rod and cone photoreceptor cells. Light reduces the concentration of cGMP, which, in darkness, keeps open cationic channels present in the plasma membrane of the o...

CALCIUM CHANNELS AT THE PHOTORECEPTOR SYNAPSE

Steven Barnes and Melanie E.M. Kelly

Presynaptic Ca²⁺ channels mediate early stages of visual information processing in photoreceptors by facilitating the release of neurotransmitter and by receiving modulatory input that alters transmission. Two types of Ltype Ca²⁺ channels, composed of

Calcium Homeostasis in Fly Photoreceptor Cells

Johannes Oberwinkler

In fly photoreceptor cells, two processes dominate the Ca²⁺ homeostasis: light-induced Ca²⁺ influx through members of the TRP family of ion channels, and Ca²⁺ extrusion by Na⁺/Ca²⁺ exchange. Ca²⁺ release from intracellular...

Calcium-Dependent Activation of Guanylate Cyclase by S100b

Ari Sitaramayya

Calcium concentration in the dark-adapted retinal rod outer segment is in the 200 to 600 nM range, and the guanylate cyclase of rod outer segments is thought to be activated in response to a fall in calcium concentration triggered by light. Calcium-binding proteins that mediate such acti...

Caldendrins in the Inner Retina

C.I. Seidenbecher, C. Reissner and M.R. Kreutz

Caldendrin is the first member of a novel family of Ca²⁺-binding proteins (CaBPs). Its unique two-domain structure is composed of a calmodulin-homologous C-terminus and an unrelated N-terminal part. The latter is thought to mediate the tight association of caldendrin with the ...

Calmodulin and Ca2+ Binding Proteins (CaBPs): Variations on a Theme

Francoise Haeseleer and Krzysztof Palczewski

Ca2+ is a ubiquitous second messenger that frequently exerts its effects through Ca2+binding proteins. In response to changes in the intracellular [Ca2+], Ca2+binding proteins modulate the cellular activities of enzymes, channels and structural proteins. Multiple Ca2+binding proteins are expressed i...

Capturing the VirA/VirG TCS of Agrobacterium tumefaciens

Yi-Han Lin, Rong Gao, Andrew N. Binns and David G. Lynn

Two‑component systems (TCS) regulate pathogenic commitment in many interactions and provide an opportunity for unique therapeutic intervention. The VirA/VirG TCS of Agrobacterium tumefaciens mediates inter‑kingdom gene transfer in the development of host tumors and sets in motion the eve...

Cell-Cell Adhesion

Vania M.M. Braga and Martha Betson

Cell-cell adhesion is an essential process for tissue architecture. During development and differentiation, intercellular adhesion provides a selective way for choosing like-neighbours and spatial cues for cell positioning within a tissue. In addition, by modulating the type and the surface le...

Cell-Cell Adhesion

Vania M.M. Braga and Martha Betson

Cell-cell adhesion is an essential process for tissue architecture. During development and differentiation, intercellular adhesion provides a selective way for choosing like-neighbours and spatial cues for cell positioning within a tissue. In addition, by modulating the type and the surface level...

Centrins, a Novel Group of Ca²⁺-Binding Proteins in Vertebrate Photoreceptor Cells

Uwe Wolfrum, Andreas Gießl, Alexander Pulvermüller

Changes in the intracellular Ca²⁺-concentration affects the visual signal transduction cascade directly or more often indirectly through Ca²⁺-binding proteins. Here we review recent findings on centrins in photoreceptor cells of the mammalian retina. Centrins are me...

Centriole Inheritance

Patricia G. Wilson

Early cell biologists perceived centrosomes to be permanent cellular structures. Centrosomes were observed to reproduce once each cycle and to orchestrate assembly of a transient mitotic apparatus that segregated chromosomes and a centrosome to each daughter at the completion of cell division....

Ceramidases: Regulators of Turnover of Ceramide and Ceramide-Mediated Responses

Cungui Mao and Lina Obeid

Ceramide has been shown to mediate various stress-induced responses such as apoptosis, growth arrest, differentiation, inflammation, and heat stress response. Regulation of these responses may rely on the net cellular levels of ceramide, which are determined by a balance between the rate...

Ceramide Glycosylation and Chemotherapy Resistance

Myles C. Cabot

Multidrug resistance, inherent or acquired, is a frequent characteristic of cancer cells and is difficult to predict and to manage. Multidrug resistance is caused by multiple mechanisms, including the dysfunctional metabolism of the lipid second messenger ceramide. The cytotoxic effect of vari...

Ceramide in Apoptosis: Possible Biophysical Foundations of Action

Paavo K. J. Kinnunen and Juha M. Holopainen

One of the conserved lipid signaling systems in multicellular organisms is the SM cycle.^1,2 The key molecule in this cascade is ceramide, which has been identified to serve as a second messenger for a variety of cellular processes, ranging from differentiation and proliferatio...

Ceramide in Apoptosis: The FAN Thesis, Not a Fantasy

Bruno Segui, Olivier Cuvillier, Sophie Malagarie-Cazenave, Sophie Levesque, Valerie Gouaze, Nathalie Andrieu-Abadie and Thierry Levade

The sphingolipid ceramide has recently been proposed as a new apoptotic cell death mediator. Here the role of the FAN (Factor Associated with Neutral sphingomyelinase activation) protein in apoptosis signal transduction is discussed. FAN was initially described to associate with the TNF ...

Ceramide in Serum Lipoproteins: Function and Regulation of Metabolism

Mariana N. Nikolova-Karakashian

Serum ceramide levels increase during the acute phase response to inflammation in animal models and in humans. Two major mechanisms appear to mediate these changes. The bacterial endotoxin, LPS, stimulates serine-palmitoyl transferase (SPT) mRNA levels and activity in liver, thus increas...

Ceramide in the Regulation of Neuronal Development: Two Faces of a Lipid

Christian Riebeling and Anthony H. Futerman

The notion proposed over a decade ago that ceramide is involved in cellular signaling events has stimulated a large number of studies that have attempted to define the precise function(s) of ceramide in signaling, and has revived interest in understanding the mechanisms of regulation of ...