Effects of F-actin stabilization or disassembly on epithelial Cl- secretion and Na-K-2Cl cotransport

Matthews, Jeffrey B.; Smith, Jeremy A.; Hrnjez, Bruce J.

doi:10.1152/ajpcell.1997.272.1.c254

Cited by 83 publications

(51 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although apical membrane Cl Ϫ channels, and in particular CFTR, are generally held to be the primary regulatory site for epithelial Cl Ϫ secretion, it is clear that Cl Ϫ uptake across the basolateral membrane must also increase to balance apical Cl Ϫ exit and to preserve intracellular ion and volume homeostasis under changing physiologic demands. We have previously identified several conditions under which the regulation of the basolateral Na-K-2Cl cotransporter appears to limit the rate of transepithelial Cl Ϫ transport (17,18,47). Our findings with butyrate-treated T84 cells further supports this concept.…”

Section: Discussionsupporting

confidence: 80%

Na-K-2Cl cotransporter gene expression and function during enterocyte differentiation. Modulation of Cl- secretory capacity by butyrate.

Matthews

Hassan²,

Meng³

et al. 1998

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

Section: Discussionsupporting

confidence: 80%

Na-K-2Cl cotransporter gene expression and function during enterocyte differentiation. Modulation of Cl- secretory capacity by butyrate.

Matthews

Hassan²,

Meng³

et al. 1998

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…For instance, patch clamp analysis revealed that phalloidin can inhibit K ϩ and Na ϩ channels (32,33). Similarly, jasplakinolide prevents the activation of Cl Ϫ secretion induced by cAMP (34), which is believed to be mediated by a conductive pathway. Cytochalasins have been found to stimulate Na…”

Section: Actin Cytoskeleton and Namentioning

confidence: 99%

The Apical Na+/H+ Exchanger Isoform NHE3 Is Regulated by the Actin Cytoskeleton

Kurashima¹,

D’Souza²,

Szászi³

et al. 1999

Journal of Biological Chemistry

110

111

View full text Add to dashboard Cite

The epithelial isoform of the Na ؉ /H ؉ exchanger, NHE3, associates with at least two related regulatory factors called NHERF1/EBP50 and NHERF2/TKA-1/ E3KARP. These factors in addition interact with the cytoskeletal protein ezrin, which in turn binds to actin. The possible linkage of NHE3 with the cytoskeleton prompted us to test the effect of actin-modifying agents on NHE3 activity. Cytochalasins B and D and latrunculin B, which interfere with actin polymerization, induced a profound inhibition of NHE3 activity. The effect was isoform-specific inasmuch as the "housekeeping" exchanger NHE1 was virtually unaffected. Cytoskeletal disorganization was associated with a subcellular redistribution of NHE3, which accumulated at sites where actin aggregated, suggesting a physical interaction of exchangers with the cytoskeleton. An interaction was further suggested by the co-sedimentation of a detergent-insoluble fraction of NHE3 with the actin cytoskeleton. Inhibition of transport was not due to diminution in the number of transporters at the plasmalemma. Functional analyses of NHE1/NHE3 chimeras revealed that the cytoplasmic domain of NHE3 conferred sensitivity to cytochalasin B. Progressive carboxyl-terminal and internal deletions of the cytoplasmic region of NHE3 indicated that the region between residues 650 and 684 is critical for this response. This region overlaps with the domain reported to interact with NHERF and also contains a putative ezrin-binding site; hence, it likely plays a role in interactions with the cytoskeleton.

show abstract

“…To elucidate whether the actin cytoskeleton was involved in cytochalasin B-induced inhibition of hKv1.5 channels, we further examined the effects of other actin disruptors, such as cytochalasin D and cytochalasin J and an actin filament stabilizer phalloidin (22,35) on the cytochalasin B-induced inhibition of hKv1.5 (Fig. 4).…”

Section: Resultsmentioning

confidence: 99%

Direct block of cloned hKv1.5 channel by cytochalasins, actin-disrupting agents

Choi¹,

Park²,

Lee³

et al. 2005

American Journal of Physiology-Cell Physiology

View full text Add to dashboard Cite

The action of cytochalasins, actin-disrupting agents on human Kv1.5 channel (hKv1.5) stably expressed in Ltk Ϫ cells was investigated using the whole cell patchclamp technique. Cytochalasin B inhibited hKv1.5 currents rapidly and reversibly at ϩ60 mV in a concentration-dependent manner with an IC 50 of 4.2 M. Cytochalasin A, which has a structure very similar to cytochalasin B, inhibited hKv1.5 (IC 50 of 1.4 M at ϩ60 mV). Pretreatment with other actin filament disruptors cytochalasin D and cytochalasin J, and an actin filament stabilizing agent phalloidin had no effect on the cytochalasin B-induced inhibition of hKv1.5 currents. Cytochalasin B accelerated the decay rate of inactivation for the hKv1.5 currents. Cytochalasin B-induced inhibition of the hKv1.5 channels was voltage dependent with a steep increase over the voltage range of the channel's opening. However, the inhibition exhibited voltage independence over the voltage range in which channels are fully activated. Cytochalasin B produced no significant effect on the steady-state activation or inactivation curves. The rate constants for association and dissociation of cytochalasin B were 3.7 M/s and 7.5 s Ϫ1 , respectively. Cytochalasin B produced a use-dependent inhibition of hKv1.5 current that was consistent with the slow recovery from inactivation in the presence of the drug. Cytochalasin B (10 M) also inhibited an ultrarapid delayed rectifier K ϩ current (IK,ur) in human atrial myocytes. These results indicate that cytochalasin B primarily blocks activated hKv1.5 channels and endogenous IK,ur in a cytoskeleton-independent manner as an open-channel blocker.

show abstract

Effects of F-actin stabilization or disassembly on epithelial Cl- secretion and Na-K-2Cl cotransport

Cited by 83 publications

References 27 publications

Na-K-2Cl cotransporter gene expression and function during enterocyte differentiation. Modulation of Cl- secretory capacity by butyrate.

Na-K-2Cl cotransporter gene expression and function during enterocyte differentiation. Modulation of Cl- secretory capacity by butyrate.

The Apical Na+/H+ Exchanger Isoform NHE3 Is Regulated by the Actin Cytoskeleton

Direct block of cloned hKv1.5 channel by cytochalasins, actin-disrupting agents

Contact Info

Product

Resources

About