Influence of W-7, a calmodulin antagonist on phospholipid biosynthesis inCandida albicans

Abstract

Aim: This study was undertaken to investigate the role of calmodulin in phospholipid biosynthesis in Candida albicans using W-7, a calmodulin antagonist. Methods: Cells were grown as shake cultures in the absence and presence of W-7 at different concentrations. Changes in cell mass, phospholipid content and incorporation of labelled precursor into phospholipid and activities of respective enzymes have been studied. Results: Decreased incorporation of labelled acetate into total lipids and phospholipids was observed in the presence of 40 lM M of W-7 which was not as a consequence of altered growth of Candida in the presence of calmodulin antagonist. Further, a significant decrease in the levels of calmodulin and CaM dependent protein kinase activity was observed in cells grown with different concentrations of W-7. This was accompanied by decreased/ increased activity of phosphatidic acid phosphatase and phospholipase A, respectively in W-7 grown cells as compared to controls. Conclusions: These findings suggest definite involvement of calmodulin in the regulation of phospholipid metabolism in Candida albicans.

Rotavirus infection induces G1 to S phase transition in MA104 cells via Ca+2/Calmodulin pathway

“…4A). To delineate relation between CaMKI activation and cell cycle progression, MA104 cells were either infected with RV SA11 strain at 3 moi or kept mock infected in presence or absence of either calcium chelator BAPTA-AM which chelates Ca þ 2 ions and inhibits CaM activation or CaM inhibitor W7 which bind selectively to CaM and inhibit its downstream functions (Dhillon et al, 2003), for indicated time points followed by cell cycle analysis using flowcytometry (treatments were done post viral absorption). Quantitive analysis revealed that both BAPTA-AM and W7 inhibit cell cycle progression from G1 to S phase as found in only SA11 infected MA104 cells (Fig.…”

Identification of Cellular Calcium Binding Protein Calmodulin as a Regulator of Rotavirus A Infection during Comparative Proteomic Study

“…9D). This effect may be due to antagonistic activity of the W-7 against the Ca 2+ -CaM complex [36] which is required for efficient viral replication & assembly.…”

“…Cytotoxicity of Fura2-AM was tested using MTT assay (data not shown) [36]. HT-29 cells were treated with increasing concentration (0–50 µM) of W-7 (in DMSO), a CaM antagonist and after 12 h, cell viability was measured (data not shown).…”