Jean-Marc Verbavatz

Learn More
Photosynthetic organisms have developed multiple protective mechanisms to survive under high-light conditions. In plants, one of these mechanisms is the thermal dissipation of excitation energy in the membrane-bound chlorophyll antenna of photosystem II. The question of whether or not cyanobacteria, the progenitor of the chloroplast, have an equivalent(More)
In this study we analyzed the expression of aquaporin-4 (AQP4) in mammalian skeletal muscle. Immunohistochemical experiments revealed that affinity-purified AQP4 antibodies stained selectively the sarcolemma of fast-twitch fibers. By immunogold electron microscopy, little or no intracellular labeling was detected. Western blot analysis showed the presence(More)
A facilitated diffusion for glycerol is present in human erythrocytes. Glycerol transporters identified to date belong to the Major Intrinsic Protein (MIP) family of integral membrane proteins, and one of them, aquaporin-3 (AQP3), has been characterized in mammals. Using an antibody raised against a peptide corresponding to the rat AQP3 carboxyl terminus,(More)
BACKGROUND Mechanoreceptors contain compliant elements, termed "gating springs," that transfer macroscopic stimuli impinging on the cells into microscopic stimuli that open the mechanosensitive channels. Evidence for gating springs comes from mechanical experiments; they have not been identified molecularly or ultrastructurally. RESULTS We show that the(More)
The aquaporins (AQPs) are a family of homologous water-channel proteins that can be inserted into epithelial cell plasma membranes either constitutively (AQP1) or by regulated exocytosis following vasopressin stimulation (AQP2). LLC-PK1 porcine renal epithelial cells were stably transfected with cDNA encoding AQP2 (tagged with a C-terminal c-Myc epitope) or(More)
Previous results showed that mRNA encoding a putative aquaporin (AQP) (GenBank accession number AF218314) is present in the tracheolar cells associated with female Aedes aegypti Malpighian tubules. In this study, immunohistochemistry detected the protein, AeaAQP, also in tracheolar cells, suggesting its involvement in water movement in the respiratory(More)
The thermophilic cyanobacterium, Thermosynechococcus elongatus, has been grown in the presence of Sr2+ instead of Ca2+ with the aim of biosynthetically replacing the Ca2+ of the oxygen-evolving enzyme with Sr2+. Not only were the cells able to grow normally with Sr2+, they actively accumulated the ion to levels higher than those of Ca2+ in the normal(More)
The loss of ultrafiltration (UF) that accompanies acute peritonitis is a common problem in peritoneal dialysis (PD). It has been suggested that changes in nitric oxide (NO)-mediated vascular tone and permeability might be involved in the loss of UF, whereas channel-mediated water permeability should not be affected. This study used a model of acute(More)
Aging is currently associated with progressive declines of cerebral functions. From these, a decreased resistance to dehydration suggested alteration in choroidal control of brain homeostasis and reduced cerebrospinal fluid (CSF) production in old subjects. In the present study, choroid plexuses of 20-month old Sprague-Dawley rats were compared with those(More)
CHIP28 is a major water transporting protein in erythrocytes and plasma membranes in kidney proximal tubule and thin descending limb of Henle. Chinese hamster ovary cells were stably transfected with the coding sequence of cloned rat kidney CHIP28k using expression vectors containing cytomegalovirus or Rous sarcoma virus promoters. Clonal cell populations(More)