{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T12:43:44Z","timestamp":1791549824226,"version":"4.3.4"},"reference-count":44,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2021,12,10]],"date-time":"2021-12-10T00:00:00Z","timestamp":1639094400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000289","name":"Cancer Research UK","doi-asserted-by":"publisher","award":["A17196"],"award-info":[{"award-number":["A17196"]}],"id":[{"id":"10.13039\/501100000289","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000289","name":"Cancer Research UK","doi-asserted-by":"publisher","award":["A20017"],"award-info":[{"award-number":["A20017"]}],"id":[{"id":"10.13039\/501100000289","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000266","name":"EPSRC","doi-asserted-by":"publisher","award":["EP\/S030875\/1"],"award-info":[{"award-number":["EP\/S030875\/1"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>The lamellipodia and pseudopodia of migrating cells are produced and maintained by the Scar\/WAVE complex. Thus, actin-based cell migration is largely controlled through regulation of Scar\/WAVE. Here, we report that the Abi subunit\u2014but not Scar\u2014is phosphorylated in response to extracellular signalling in Dictyostelium cells. Like Scar, Abi is phosphorylated after the complex has been activated, implying that Abi phosphorylation modulates pseudopodia, rather than causing new ones to be made. Consistent with this, Scar complex mutants that cannot bind Rac are also not phosphorylated. Several environmental cues also affect Abi phosphorylation\u2014cell-substrate adhesion promotes it and increased extracellular osmolarity diminishes it. Both unphosphorylatable and phosphomimetic Abi efficiently rescue the chemotaxis of Abi KO cells and pseudopodia formation, confirming that Abi phosphorylation is not required for activation or inactivation of the Scar\/WAVE complex. However, pseudopodia and Scar patches in the cells with unphosphorylatable Abi protrude for longer, altering pseudopod dynamics and cell speed. Dictyostelium, in which Scar and Abi are both unphosphorylatable, can still form pseudopods, but migrate substantially faster. We conclude that extracellular signals and environmental responses modulate cell migration by tuning the behaviour of the Scar\/WAVE complex after it has been activated.<\/jats:p>","DOI":"10.3390\/cells10123485","type":"journal-article","created":{"date-parts":[[2021,12,10]],"date-time":"2021-12-10T08:17:58Z","timestamp":1639124278000},"page":"3485","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Extracellular Signalling Modulates Scar\/WAVE Complex Activity through Abi Phosphorylation"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6029-8115","authenticated-orcid":false,"given":"Shashi Prakash","family":"Singh","sequence":"first","affiliation":[{"name":"CRUK Beatson Institute, Glasgow G61 1BD, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter A.","family":"Thomason","sequence":"additional","affiliation":[{"name":"CRUK Beatson Institute, Glasgow G61 1BD, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4898-040X","authenticated-orcid":false,"given":"Robert H.","family":"Insall","sequence":"additional","affiliation":[{"name":"CRUK Beatson Institute, Glasgow G61 1BD, UK"},{"name":"Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1QH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1038\/nrm3861","article-title":"Steering cell migration: Lamellipodium dynamics and the regulation of directional persistence","volume":"15","author":"Krause","year":"2014","journal-title":"Nat. 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