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Continuous phosphatidylinositol metabolism is required for cleavage of crane fly spermatocytes.
J Cell Sci. 2004 Aug 01; 117(Pt 17):3887-96.JC

Abstract

Successful cleavage of animal cells requires co-ordinated regulation of the actomyosin contractile ring and cleavage furrow ingression. Data from a variety of systems implicate phosphoinositol lipids and calcium release as potential regulators of this fundamental process. Here we examine the requirement for various steps of the phosphatidylinositol (PtdIns) cycle in dividing crane fly (Nephrotoma suturalis) spermatocytes. PtdIns cycle inhibitors were added to living cells after cleavage furrows formed and began to ingress. Inhibitors known to block PtdIns recycling (lithium), PtdIns phosphorylation (wortmannin, LY294002) or phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] hydrolysis [U73122 (U7)] all stopped or slowed furrowing. The effect of these drugs on cytokinesis was quite rapid (within 0-4 minutes), so continuous metabolism of PtdIns appears to be required for continued cleavage furrow ingression. U7 caused cleavage furrow regression concomitant with depletion of F-actin from the contractile ring, whereas the other inhibitors caused neither regression nor depletion of F-actin. That U7 depletes furrow-associated actin seems counterintuitive, as inhibition of phospholipase C would be expected to increase cellular levels of PtdIns(4,5)P(2) and hence increase actin polymerization. Our confocal images suggest, however, that F-actin might accumulate at the poles of U7-treated cells, consistent with the idea that PtdIns(4,5)P(2) hydrolysis may be required for actin filaments formed at the poles to participate in contractile ring assembly at the furrow.

Authors+Show Affiliations

Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15265984

Citation

Saul, Daniel, et al. "Continuous Phosphatidylinositol Metabolism Is Required for Cleavage of Crane Fly Spermatocytes." Journal of Cell Science, vol. 117, no. Pt 17, 2004, pp. 3887-96.
Saul D, Fabian L, Forer A, et al. Continuous phosphatidylinositol metabolism is required for cleavage of crane fly spermatocytes. J Cell Sci. 2004;117(Pt 17):3887-96.
Saul, D., Fabian, L., Forer, A., & Brill, J. A. (2004). Continuous phosphatidylinositol metabolism is required for cleavage of crane fly spermatocytes. Journal of Cell Science, 117(Pt 17), 3887-96.
Saul D, et al. Continuous Phosphatidylinositol Metabolism Is Required for Cleavage of Crane Fly Spermatocytes. J Cell Sci. 2004 Aug 1;117(Pt 17):3887-96. PubMed PMID: 15265984.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Continuous phosphatidylinositol metabolism is required for cleavage of crane fly spermatocytes. AU - Saul,Daniel, AU - Fabian,Lacramioara, AU - Forer,Arthur, AU - Brill,Julie A, Y1 - 2004/07/20/ PY - 2004/7/22/pubmed PY - 2005/4/5/medline PY - 2004/7/22/entrez SP - 3887 EP - 96 JF - Journal of cell science JO - J. Cell. Sci. VL - 117 IS - Pt 17 N2 - Successful cleavage of animal cells requires co-ordinated regulation of the actomyosin contractile ring and cleavage furrow ingression. Data from a variety of systems implicate phosphoinositol lipids and calcium release as potential regulators of this fundamental process. Here we examine the requirement for various steps of the phosphatidylinositol (PtdIns) cycle in dividing crane fly (Nephrotoma suturalis) spermatocytes. PtdIns cycle inhibitors were added to living cells after cleavage furrows formed and began to ingress. Inhibitors known to block PtdIns recycling (lithium), PtdIns phosphorylation (wortmannin, LY294002) or phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] hydrolysis [U73122 (U7)] all stopped or slowed furrowing. The effect of these drugs on cytokinesis was quite rapid (within 0-4 minutes), so continuous metabolism of PtdIns appears to be required for continued cleavage furrow ingression. U7 caused cleavage furrow regression concomitant with depletion of F-actin from the contractile ring, whereas the other inhibitors caused neither regression nor depletion of F-actin. That U7 depletes furrow-associated actin seems counterintuitive, as inhibition of phospholipase C would be expected to increase cellular levels of PtdIns(4,5)P(2) and hence increase actin polymerization. Our confocal images suggest, however, that F-actin might accumulate at the poles of U7-treated cells, consistent with the idea that PtdIns(4,5)P(2) hydrolysis may be required for actin filaments formed at the poles to participate in contractile ring assembly at the furrow. SN - 0021-9533 UR - https://www.unboundmedicine.com/medline/citation/15265984/Continuous_phosphatidylinositol_metabolism_is_required_for_cleavage_of_crane_fly_spermatocytes_ L2 - http://jcs.biologists.org/cgi/pmidlookup?view=long&pmid=15265984 DB - PRIME DP - Unbound Medicine ER -