CLIC-5A Functions as a Chloride Channel in Vitro and Associates with the Cortical Actin Cytoskeleton in Vitro and in Vivo

Berryman, Mark; Bruno, Jonathan; Price, Jessica; Edwards, John C.

doi:10.1074/jbc.m402835200

Cited by 80 publications

(98 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In mature osteoclasts c-Src and F-actin are concentrated along the H ϩ -secreting ruffled border (33, 77) and the v-H ϩ -ATPase and Src co-localize with the cytoskeleton (78). Recently CLIC-5 protein has been shown to associate with F-actin and specifically the c-Src substrate ezrin in placental microvilli (42). We have studied binding between CLIC-5b and c-Src as well as the relationship between c-Src suppression and Hϩ transport in osteoclast membranes.…”

Section: Volume 281 • Number 38 • September 22 2006mentioning

confidence: 99%

See 1 more Smart Citation

c-Src Control of Chloride Channel Support for Osteoclast HCl Transport and Bone Resorption

Edwards

Cohen

et al. 2006

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Bone degradation by osteoclasts depends upon active transport of hydrogen ions to solubilize bone mineral. This transport is supported by the parallel actions of a proton ATPase and a chloride channel located in the osteoclast ruffled membrane. We have previously identified a novel chloride channel, p62, which appears to be the avian counterpart to CLIC-5b and is expressed coincident with the appearance of acid secretion as avian osteoclasts differentiate in culture. In this article, we show that suppression of CLIC-5b in differentiating avian osteoclasts results in decreased acidification by vesicles derived from these cells and decreased ability of the cells to resorb bone. Acidification is rescued by the presence of valinomycin, consistent with a selective loss of chloride channel but not proton pump activity. Osteoclast bone resorption is known to be dependent on the expression of the tyrosine kinase, c-Src. We show that CLIC-5b from osteoclasts has affinity for both Src SH2 and SH3 domains. We find that suppression of expression of Src in developing osteoclasts results in decreased vesicular acidification, which is rescued by valinomycin, consistent with the loss of chloride conductance in the proton pump-containing vesicles. Suppression of c-Src causes no change in the steady state level of CLIC-5b expression, but does result in failure of proton pump and CLIC-5b to colocalize in cultured osteoclast precursors. We conclude that suppression of c-Src interferes with osteoclast bone resorption by disrupting functional co-localization of proton pump and CLIC-5b.Skeleton integrity requires that osteoclast-mediated bone resorption be intact and regulated (1). Osteoclasts can remodel bone because these multinucleated cells secret sufficient acid into the resorption compartment to solubilize bone mineral (2, 3), an alkaline salt that becomes increasingly soluble at pH values below 6 (4, 5). The resorption compartment is delineated by a circumferential tightly adherent sealing zone (6). The osteoclast plasma membrane enclosed within the sealing zone differentiates into a highly specialized structure, the ruffled border. Across this membrane the cell actively transports HCl, which dissolves bone mineral and activates acid hydrolases required for bone resorption (7,8). The transport of HCl occurs in two steps. An electrogenic ATP-dependent proton pump (9 -12), inserts H ϩ into the resorption compartment. Chloride ions follow passively through a parallel chloride conductance, short circuiting the electrogenic pump and allowing the massive HCl secretion necessary during bone resorption (10).We had previously identified a 62-kDa protein, p62, from avian osteoclast ruffled border that could be reconstituted to form a DNDS 2 -sensitive chloride channel (13). This protein is antigenically related to bovine CLIC-5b, a chloride channel of bovine kidney microsomal membranes (14). Expression of avian p62 in differentiating avian osteoclasts is coincident with the appearance of outwardly rectifying chloride conductance, valinom...

show abstract

Section: Volume 281 • Number 38 • September 22 2006mentioning

confidence: 99%

“…Mammals have 6 distinct CLIC genes, named CLIC 1 through 6. Bovine p64 is a product of the CLIC-5 gene (14,42). We used bovine p64-specific probes to identify CLIC-related sequences in cDNA from avian osteoclasts.…”

Section: Proton Pump and Chloride Permeability In Hcl Transport Bymentioning

confidence: 99%

c-Src Control of Chloride Channel Support for Osteoclast HCl Transport and Bone Resorption

Edwards

Cohen

et al. 2006

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…The CLIC family consists of seven proteins (Shanks et al, 2002), with CLICs 1, 4, and 5 known to possess chloride channel activity (Tonini et al, 2000;Tulk et al, 2002;Berryman et al, 2004;Singh and Ashley, 2006). CLIC1 was originally identified in monocytes (Valenzuela et al, 1997) and is able to insert into membranes from the aqueous phase (Tulk et al, 2002;Warton et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

CLIC1 Function Is Required for β-Amyloid-Induced Generation of Reactive Oxygen Species by Microglia

Milton¹,

Abeti²,

Averaimo³

et al. 2008

J. Neurosci.

129

131

View full text Add to dashboard Cite

The Alzheimer's disease (AD) brain is characterized by plaques containing ␤-amyloid (A␤) protein surrounded by astrocytes and reactive microglia. Activation of microglia by A␤ initiates production of reactive oxygen species (ROS) by the plasmalemmal NADPH oxidase; the resultant oxidative stress is thought to contribute to neurodegeneration in AD. We have previously shown that A␤ upregulates a chloride current mediated by the chloride intracellular channel 1 (CLIC1) protein in microglia. We now demonstrate that A␤ promotes the acute translocation of CLIC1 from the cytosol to the plasma membrane of microglia, where it mediates a chloride conductance. Both the A␤ induced Cl Ϫ conductance and ROS generation were prevented by pharmacological inhibition of CLIC1, by replacement of chloride with impermeant anions, by an anti-CLIC1 antibody and by suppression of CLIC1 expression using siRNA. Thus, the CLIC1-mediated Cl Ϫ conductance is required for A␤-induced generation of neurotoxic ROS by microglia. Remarkably, CLIC1 activation is itself dependent on oxidation by ROS derived from the activated NADPH oxidase. We therefore propose that CLIC1 translocation from the cytosol to the plasma membrane, in response to redox modulation by NADPH oxidase-derived ROS, provides a feedforward mechanism that facilitates sustained microglial ROS generation by the NAPDH oxidase.

show abstract

“…There is a pervasive cytoskeletal-src dependence of proper targeting for the ion transporters of osteoclasts [Zuo et al, 2006: Tehrani et al, 2006: Abu-Amer et al, 1997: Soriano et al, 1991. The actindirected disposition of CLIC protein has also been observed in microvilli of placental cells [Berryman et al, 2004]. In osteoclasts the coordinated disposition of V-ATPase and CLIC required for full expression of the bone resorption phenotype [Edwards et al, 2006].…”

Section: Bulk Calcium Transport By the Osteoclastmentioning

confidence: 99%

Calcium Signalling and Calcium Transport in Bone Disease

Blair

Schlesinger

Huang

et al.

Subcellular Biochemistry

View full text Add to dashboard Cite

Calcium transport and calcium signalling mechanisms in bone cells have, in many cases, been discovered by study of diseases with disordered bone metabolism. Calcium matrix deposition is driven primarily by phosphate production, and disorders in bone deposition include abnormalities in membrane phosphate transport such as in chondrocalcinosis, and defects in phosphate-producing enzymes such as in hypophosphatasia. Matrix removal is driven by acidification, which dissolves the mineral. Disorders in calcium removal from bone matrix by osteoclasts cause osteopetrosis. On the other hand, although bone is central to management of extracellular calcium, bone is not a major calcium sensing organ, although calcium sensing proteins are expressed in both osteoblasts and osteoclasts. Intracellular calcium signals are involved in secondary control including cellular motility and survival, but the relationship of these findings to specific diseases is not clear. Intracellular calcium signals may regulate the balance of cell survival versus proliferation or anabolic functional response as part of signalling cascades that integrate the response to primary signals via cell stretch, estrogen, tyrosine kinase, and tumor necrosis factor receptors Keywords Hypophosphatasia; chondrocalcinosis; osteopetrosis; osteoporosis Although bone is not considered a major calcium sensing organ in humans, the cells of bone tissue control over 99% of the human body's calcium content. The principal calcium sensors that regulate bone calcium uptake and release are in the parathyroid glands. Bone function is also modified by vitamin D and by calcium transport in the kidney and intestine. These indirect mechanisms of controlling bone calcium metabolism are beyond the scope of our considerations here. In spite of processing such massive quantities of the Ca 2+ bone cells use calcium in their homeostatic control processes. The massive movement of calcium is carried out by specialized and regulated transporters. Defects in the transporters cause diseases with affect bone structure or function. Indeed, inborn errors have been very important in defining the calcium transport mechanisms in bone.Additionally, calcium is used by bone forming and bone degrading cells as a secondary mediator of hormone and cytokine action. These actions include roles in intercellular communication within groups of osteoblasts, which are connected by gap junctions [Henriksen et al., 2006]. These osteoblast groups function in a coordinated fashion in bone synthesis and maintenance, and are collectively known as the osteon. Osteoblasts in these groups are connected by gap junctions which are capable of propagating signals in the cell groups, including calcium waves [Xia and Ferrier, 1992]. Calcium is also an important regulator of

show abstract

CLIC-5A Functions as a Chloride Channel in Vitro and Associates with the Cortical Actin Cytoskeleton in Vitro and in Vivo

Cited by 80 publications

References 31 publications

c-Src Control of Chloride Channel Support for Osteoclast HCl Transport and Bone Resorption

c-Src Control of Chloride Channel Support for Osteoclast HCl Transport and Bone Resorption

CLIC1 Function Is Required for β-Amyloid-Induced Generation of Reactive Oxygen Species by Microglia

Calcium Signalling and Calcium Transport in Bone Disease

Contact Info

Product

Resources

About