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Article
Ponticulin plays a role in the positional stabilization of pseudopods
Women’s Health Research Faculty Publications
  • D. C. Shutt
  • D. Wessels
  • K. Wagenknecht
  • A. Chandrasekhar
  • Anne L. Hitt
  • Elizabeth J. Luna, University of Massachusetts Medical School
  • D. R. Soll
UMMS Affiliation
Department of Cell Biology
Date
12-1-1995
Document Type
Article
Subjects
Actins; Animals; Carrier Proteins; Cell Movement; Cell Size; Chemotaxis; Dictyostelium; Microfilament Proteins; Mutation; Pseudopodia
Abstract

Ponticulin is a 17-kD glycoprotein that represents a major high affinity link between the plasma membrane and the cortical actin network of Dictyostelium. To assess the role of ponticulin in pseudopod extension and retraction, the motile behavior of two independently generated mutants lacking ponticulin was analyzed using computer-assisted two- and three-dimensional motion analysis systems. More than half of the lateral pseudopods formed off the substratum by ponticulin-minus cells slipped relative to the substratum during extension and retraction. In contrast, all pseudopods formed off the substratum by wild-type cells were positionally fixed in relation to the substratum. Ponticulin-minus cells also formed a greater proportion of both anterior and lateral pseudopods off the substratum and absorbed a greater proportion of lateral pseudopods into the uropod than wild-type cells. In a spatial gradient of cAMP, ponticulin-minus cells were less efficient in tracking the source of chemoattractant. Since ponticulin-minus cells extend and retract pseudopods with the same time course as wild-type cells, these behavioral defects in ponticulin-minus cells appear to be the consequence of pseudopod slippage. These results demonstrate that pseudopods formed off the substratum by wild-type cells are positionally fixed in relation to the substratum, that ponticulin is required for positional stabilization, and that the loss of ponticulin and the concomitant loss of positional stability of pseudopods correlate with a decrease in the efficiency of chemotaxis.

Rights and Permissions
Citation: J Cell Biol. 1995 Dec;131(6 Pt 1):1495-506. Link to article on publisher's website
Related Resources
Link to article in PubMed
PubMed ID
8522606
Citation Information
D. C. Shutt, D. Wessels, K. Wagenknecht, A. Chandrasekhar, et al.. "Ponticulin plays a role in the positional stabilization of pseudopods" Vol. 131 Iss. 6 Pt 1 (1995) ISSN: 0021-9525 (Print)
Available at: http://works.bepress.com/lunae/32/