Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells.
IQGAP1 interacts with a number of binding partners through a calponin homology domain (CHD), a WW motif, IQ repeats, a Ras GAP-related domain (GRD), and a conserved C-terminal (CT) domain. Among various biological and cellular functions, IQGAP1 is known to play a role in actin cytoskeleton dynamics...
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| Format: | Article |
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Public Library of Science (PLoS)
2017-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC5730206?pdf=render |
| _version_ | 1818957417081208832 |
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| author | Michael Reimer Elisabeth Denby Silviya P Zustiak Joseph M Schober |
| author_facet | Michael Reimer Elisabeth Denby Silviya P Zustiak Joseph M Schober |
| author_sort | Michael Reimer |
| collection | DOAJ |
| description | IQGAP1 interacts with a number of binding partners through a calponin homology domain (CHD), a WW motif, IQ repeats, a Ras GAP-related domain (GRD), and a conserved C-terminal (CT) domain. Among various biological and cellular functions, IQGAP1 is known to play a role in actin cytoskeleton dynamics during membrane ruffling and lamellipodium protrusion. In addition, phosphorylation near the CT domain is thought to control IQGAP1 activity through regulation of intramolecular interaction. In a previous study, we discovered that IQGAP1 preferentially localizes to retracting areas in B16F10 mouse melanoma cells, not areas of membrane ruffling and lamellipodium protrusion. Nothing is known of the domains needed for retraction localization and very little is known of IQGAP1 function in the actin cytoskeleton of melanoma cells. Thus, we examined localization of IQGAP1 mutants to retracting areas, and characterized knock down phenotypes on tissue culture plastic and physiologic-stiffness hydrogels. Localization of IQGAP1 mutants (S1441E/S1443D, S1441A/S1443A, ΔCHD, ΔGRD or ΔCT) to retracting and protruding cell edges were measured. In retracting areas there was a decrease in S1441A/S1443A, ΔGRD and ΔCT localization, a minor decrease in ΔCHD localization, and normal localization of the S1441E/S1443D mutant. In areas of cell protrusion just behind the lamellipodium leading edge, we surprisingly observed both ΔGRD and ΔCT localization, and increased number of microtubules. IQGAP1 knock down caused loss of cell polarity on laminin-coated glass, decreased proliferation on tissue culture polystyrene, and abnormal spheroid growth on laminin-coated hydrogels. We propose that the GRD and CT domains regulate IQGAP1 localization to retracting actin networks to promote a tumorigenic role in melanoma cells. |
| first_indexed | 2024-12-20T11:09:31Z |
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| id | doaj.art-379d46e86c394862865892ffcf3bad77 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-20T11:09:31Z |
| publishDate | 2017-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-379d46e86c394862865892ffcf3bad772022-12-21T19:42:49ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-011212e018958910.1371/journal.pone.0189589Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells.Michael ReimerElisabeth DenbySilviya P ZustiakJoseph M SchoberIQGAP1 interacts with a number of binding partners through a calponin homology domain (CHD), a WW motif, IQ repeats, a Ras GAP-related domain (GRD), and a conserved C-terminal (CT) domain. Among various biological and cellular functions, IQGAP1 is known to play a role in actin cytoskeleton dynamics during membrane ruffling and lamellipodium protrusion. In addition, phosphorylation near the CT domain is thought to control IQGAP1 activity through regulation of intramolecular interaction. In a previous study, we discovered that IQGAP1 preferentially localizes to retracting areas in B16F10 mouse melanoma cells, not areas of membrane ruffling and lamellipodium protrusion. Nothing is known of the domains needed for retraction localization and very little is known of IQGAP1 function in the actin cytoskeleton of melanoma cells. Thus, we examined localization of IQGAP1 mutants to retracting areas, and characterized knock down phenotypes on tissue culture plastic and physiologic-stiffness hydrogels. Localization of IQGAP1 mutants (S1441E/S1443D, S1441A/S1443A, ΔCHD, ΔGRD or ΔCT) to retracting and protruding cell edges were measured. In retracting areas there was a decrease in S1441A/S1443A, ΔGRD and ΔCT localization, a minor decrease in ΔCHD localization, and normal localization of the S1441E/S1443D mutant. In areas of cell protrusion just behind the lamellipodium leading edge, we surprisingly observed both ΔGRD and ΔCT localization, and increased number of microtubules. IQGAP1 knock down caused loss of cell polarity on laminin-coated glass, decreased proliferation on tissue culture polystyrene, and abnormal spheroid growth on laminin-coated hydrogels. We propose that the GRD and CT domains regulate IQGAP1 localization to retracting actin networks to promote a tumorigenic role in melanoma cells.http://europepmc.org/articles/PMC5730206?pdf=render |
| spellingShingle | Michael Reimer Elisabeth Denby Silviya P Zustiak Joseph M Schober Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. PLoS ONE |
| title | Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. |
| title_full | Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. |
| title_fullStr | Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. |
| title_full_unstemmed | Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. |
| title_short | Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. |
| title_sort | ras gap related and c terminal domain dependent localization and tumorigenic activities of iqgap1 in melanoma cells |
| url | http://europepmc.org/articles/PMC5730206?pdf=render |
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