{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T23:01:52Z","timestamp":1787007712362,"version":"build-2736575974"},"reference-count":43,"publisher":"Rockefeller University Press","issue":"4","content-domain":{"domain":["rupress.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2012,8,20]]},"abstract":"<jats:p>Under normal conditions, the Arp2\/3 complex activator SCAR\/WAVE controls actin polymerization in pseudopods, whereas Wiskott\u2013Aldrich syndrome protein (WASP) assembles actin at clathrin-coated pits. We show that, unexpectedly, Dictyostelium discoideum SCAR knockouts could still spread, migrate, and chemotax using pseudopods driven by the Arp2\/3 complex. In the absence of SCAR, some WASP relocated from the coated pits to the leading edge, where it behaved with similar dynamics to normal SCAR, forming split pseudopods and traveling waves. Pseudopods colocalized with active Rac, whether driven by WASP or SCAR, though Rac was activated to a higher level in SCAR mutants. Members of the SCAR regulatory complex, in particular PIR121, were not required for WASP regulation. We thus show that WASP is able to respond to all core upstream signals and that regulators coupled through the other members of SCAR\u2019s regulatory complex are not essential for pseudopod formation. We conclude that WASP and SCAR can regulate pseudopod actin using similar mechanisms.<\/jats:p>","DOI":"10.1083\/jcb.201205058","type":"journal-article","created":{"date-parts":[[2012,8,13]],"date-time":"2012-08-13T21:48:11Z","timestamp":1344894491000},"page":"501-508","update-policy":"https:\/\/doi.org\/10.1083\/jcb.crossmarkpolicy","source":"Crossref","is-referenced-by-count":93,"title":["SCAR knockouts in\n                    <i>Dictyostelium<\/i>\n                    : WASP assumes SCAR\u2019s position and upstream regulators in pseudopods"],"prefix":"10.1083","volume":"198","author":[{"given":"Douwe M.","family":"Veltman","sequence":"first","affiliation":[{"name":"Beatson Institute for Cancer Research, Glasgow G61 1BD, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jason S.","family":"King","sequence":"additional","affiliation":[{"name":"Beatson Institute for Cancer Research, Glasgow G61 1BD, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura M.","family":"Machesky","sequence":"additional","affiliation":[{"name":"Beatson Institute for Cancer Research, Glasgow G61 1BD, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert H.","family":"Insall","sequence":"additional","affiliation":[{"name":"Beatson Institute for Cancer Research, Glasgow G61 1BD, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"291","published-online":{"date-parts":[[2012,8,13]]},"reference":[{"key":"2023072307321298900_bib1","doi-asserted-by":"publisher","first-page":"193","DOI":"10.1038\/ncb1536","article-title":"Chemotaxis in shallow gradients is mediated independently of PtdIns 3-kinase by biased choices between random protrusions","volume":"9","author":"Andrew","year":"2007","journal-title":"Nat. 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