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TSUJITA KazuyaBiosignal Research CenterAssociate Professor
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- The small GTPase Ras on the plasma membrane (PM) activates the ERK pathway (Raf–MEK–ERK signaling pathway) to regulate a variety of cellular, physiological, and pathological events. DA-Raf1 (DA-Raf) is a splicing isoform of A-Raf and contains the Ras-binding domain and the Cys-rich domain but lacks the conserved region 2 (CR2) and CR3 containing the kinase domain. Accordingly, DA-Raf dominant-negatively regulates Raf proteins to prevent the Ras–ERK pathway. We elucidate here the mechanisms of how DA-Raf conducts its dominant-negative function on Raf proteins. Because DA-Raf lacks the CR2 and CR3, it was incapable of adopting the autoinhibitory closed conformation and thereby favorable for PM localization. Basic amino acids in DA-Raf Ras-binding domain, and those in the Cys-rich domain, were essential for the interaction with phosphatidylserine in the PM. This interaction favored the cooperative binding of DA-Raf to active Ras, which predominated over that of Raf proteins, leading to the stable PM association of DA-Raf. Consequently, DA-Raf exerts its dominant-negative function on Raf proteins to prevent the Ras–ERK pathway.Life Science Alliance, LLC, Oct. 2025, Life Science Alliance, 8(12) (12), e202503300 - e202503300Scientific journal
- Osteoclasts are multinucleated giant cells that are formed by the fusion of precursor cells. Cell-cell fusion is mediated by membrane protrusion driven by actin reorganization, but the role of membrane mechanics in this process is unknown. Utilizing live-cell imaging, optical tweezers, manipulation of membrane-to-cortex attachment (MCA), and genetic interference, we show that a decrease in plasma membrane (PM) tension is a mechanical prerequisite for osteoclast fusion. Upon RANKL-induced differentiation, ezrin expression in fusion progenitor cells is reduced, resulting in a decrease in MCA-dependent PM tension. A forced elevation of PM tension by reinforcing the MCA conversely suppresses cell-cell fusion. Mechanistically, reduced PM tension leads to membrane protrusive invadosome formation driven by membrane curvature-inducing/sensing BAR proteins, thereby promoting cell-cell fusion. These findings provide insights into the mechanism of cell-cell fusion under the control of membrane mechanics.Corresponding, Jul. 2025, The Journal of cell biology, 224(7) (7), English, International magazine[Refereed]Scientific journal
- The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein has the ability to induce multinucleated syncytia via cell-cell fusion, which is thought to be related to the pathogenesis of the coronavirus disease 2019 (COVID-19). However, the mechanism by which spike protein regulates cell fusion remains unclear. Given the close correlation between cell-cell fusion and membrane protrusions, we investigated the role of membrane-proximal actin regulators in spike-induced cell fusion. We found that while Rac-Arp2/3 dependent branched actin polymerization is required for spike-mediated cell fusion, RhoA dependent actomyosin contractility has an inhibitory effect on fusion. In addition, plasma membrane tension regulated by membrane-cortex attachment plays a negative role in spike-dependent cell fusion. Furthermore, we identified several BAR proteins, which couple membrane curvature with actin dynamics, involved in spike-induced syncytia formation. Our study suggests that these actin regulators could be promising targets for inhibiting SARS-CoV-2 spike protein-induced syncytia formation.Corresponding, Jun. 2025, Biochemical and biophysical research communications, 766, 151846 - 151846, English, International magazine[Refereed]Scientific journal
- Corresponding, Elsevier BV, Apr. 2023, Current Opinion in Cell Biology, 81, 102173 - 102173[Refereed]Scientific journal
- Angiogenesis is regulated in coordinated fashion by chemical and mechanical cues acting on endothelial cells (ECs). However, the mechanobiological mechanisms of angiogenesis remain unknown. Herein, we demonstrate a crucial role of blood flow-driven intraluminal pressure (IP) in regulating wound angiogenesis. During wound angiogenesis, blood flow-driven IP loading inhibits elongation of injured blood vessels located at sites upstream from blood flow, while downstream injured vessels actively elongate. In downstream injured vessels, F-BAR proteins, TOCA1 and CIP4, localize at leading edge of ECs to promote N-WASP-dependent Arp2/3 complex-mediated actin polymerization and front-rear polarization for vessel elongation. In contrast, IP loading expands upstream injured vessels and stretches ECs, preventing leading edge localization of TOCA1 and CIP4 to inhibit directed EC migration and vessel elongation. These data indicate that the TOCA family of F-BAR proteins are key actin regulatory proteins required for directed EC migration and sense mechanical cell stretching to regulate wound angiogenesis.May 2022, Nature communications, 13(1) (1), 2594 - 2594, English, International magazine[Refereed]Scientific journal
- Epithelial cells provide cell-cell adhesion that is essential to maintain the integrity of multicellular organisms. Epithelial cell-characterizing proteins, such as epithelial junctional proteins and transcription factors are well defined. However, the role of lipids in epithelial characterization remains poorly understood. Here we show that the phospholipid phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] is enriched in the plasma membrane (PM) of epithelial cells. Epithelial cells lose their characteristics upon depletion of PM PI(4,5)P2, and synthesis of PI(4,5)P2 in the PM results in the development of epithelial-like morphology in osteosarcoma cells. PM localization of PARD3 is impaired by depletion of PM PI(4,5)P2 in epithelial cells, whereas expression of the PM-targeting exocyst-docking region of PARD3 induces osteosarcoma cells to show epithelial-like morphological changes, suggesting that PI(4,5)P2 regulates epithelial characteristics by recruiting PARD3 to the PM. These results indicate that a high level of PM PI(4,5)P2 plays a crucial role in the maintenance of epithelial characteristics.May 2022, Nature communications, 13(1) (1), 2347 - 2347, English, International magazine[Refereed]Scientific journal
- Malignancy is associated with changes in cell mechanics that contribute to extensive cell deformation required for metastatic dissemination. We hypothesized that the cell-intrinsic physical factors that maintain epithelial cell mechanics could function as tumor suppressors. Here we show, using optical tweezers, genetic interference, mechanical perturbations, and in vivo studies, that epithelial cells maintain higher plasma membrane (PM) tension than their metastatic counterparts and that high PM tension potently inhibits cancer cell migration and invasion by counteracting membrane curvature sensing/generating BAR family proteins. This tensional homeostasis is achieved by membrane-to-cortex attachment (MCA) regulated by ERM proteins, whose disruption spontaneously transforms epithelial cells into a mesenchymal migratory phenotype powered by BAR proteins. Consistently, the forced expression of epithelial-mesenchymal transition (EMT)-inducing transcription factors results in decreased PM tension. In metastatic cells, increasing PM tension by manipulating MCA is sufficient to suppress both mesenchymal and amoeboid 3D migration, tumor invasion, and metastasis by compromising membrane-mediated mechanosignaling by BAR proteins, thereby uncovering a previously undescribed mechanical tumor suppressor mechanism.Corresponding, Oct. 2021, Nature communications, 12(1) (1), 5930 - 5930, English, International magazine[Refereed]Scientific journal
- The balance between phosphoinositides distributed at specific sites in the plasma membrane causes polarized actin polymerization. Oncogenic transformations affect this balance by regulating phosphoinositide 3-kinase (PI3K) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN), causing metastatic behavior in cancer cells. Here, we show that the PTEN tumor suppressor gene is required for epithelial cancer cell invasion. Loss of PTEN in Ras-transformed MDCK cells suppressed their migratory phenotype in collagen gel and invasion through Matrigel. Rescue experiments showed a requirement for the C2 domain-mediated membrane recruitment of PTEN, which is typically observed at the rear side of invading cancer cells. These findings support the role of PTEN in suppression of unwanted leading edges necessary for efficient migration of epithelial cancer cells.Wiley, May 2021, FEBS Letters, 595(9) (9), 1303 - 1312, English, International magazine[Refereed]Scientific journal
- Oncogenic transformation enables cells to behave differently from their neighboring normal cells. Both cancer and normal cells recognize each other, often promoting the extrusion of the former from the epithelial cell layer. Here, we show that RasV12-transformed normal rat kidney 52E (NRK-52E) cells are extruded towards the basal side of the surrounding normal cells, which is concomitant with enhanced motility. The active migration of the basally extruded RasV12 cells is observed when surrounded by normal cells, indicating a non-cell-autonomous mechanism. Furthermore, specific inhibitor treatment and knockdown experiments elucidate the roles of PI3K and myosin IIA in the basal extrusion of Ras cells. Our findings reveal a new aspect of cancer cell invasion mediated by functional interactions with surrounding non-transformed cells.Elsevier BV, Mar. 2021, Biochemical and Biophysical Research Communications, 543, 15 - 22, English, International magazine[Refereed]Scientific journal
- Ubiquitinated membrane proteins such as epidermal growth factor receptor (EGFR) are delivered to early endosomes and then sorted to lysosomes via multivesicular bodies (MVBs) for degradation. The regulatory mechanism underlying formation of intralumenal vesicles en route to generation of MVBs is not fully understood. In this study, we found that SH3YL1, a phosphoinositide-binding protein, had a vesicular localization pattern overlapping with internalized EGF in endosomes in the degradative pathway. Deficiency of SH3YL1 prevents EGF trafficking from early to late endosomes and inhibits degradation of EGFR. Moreover, we show that SH3YL1 mediates EGFR sorting into MVBs in a manner dependent on its C-terminal SH3 domain, which is necessary for the interaction with an ESCRT-I component, Vps37B. Taken together, our observations reveal an indispensable role of SH3YL1 in MVB sorting and EGFR degradation mediated by ESCRT complexes.Sep. 2019, Journal of Cell Science, 132(19) (19), English, International magazine[Refereed]Scientific journal
- Tension in cell membranes is closely related to various cellular events, including cell movement and morphogenesis. Therefore, modulation of membrane tension can be a new approach for manipulating cellular events. Here, we show that an amphipathic peptide derived from the influenza M2 protein (M2[45-62]) yields lamellipodia at multiple sites in the cell. Effect of M2[45-62] on cell membrane tension was evaluated by optical tweezer. The membrane tension sensor protein FBP17 was involved in M2[45-62]-driven lamellipodium formation. Lysine-to-arginine substitution in M2[45-62] further enhanced its activity of lamellipodium formation. M2[45-62] had an ability to reduce cell motility, evaluated by scratch wound migration and transwell migration assays. An increase in neurite outgrowth was also observed after treatment with M2[45-62]. The above results suggest the potential of M2[45-62] to modulate cell movement and morphology by modulating cell membrane tension.2019, Communications Biology, 2, 243 - 243, English, International magazine[Refereed]Scientific journal
- In order for the cell to function well within a multicellular system, the mechanical properties of the plasma membrane need to meet two different requirements: cell shape maintenance and rearrangement. To achieve these goals, phosphoinositides play key roles in the regulation of the cortical actin cytoskeleton. PI(4,5)P₂is the most abundant phosphoinositide species in the plasma membrane. It maintains cell shape by linking the actin cortex to the membrane via interactions with Ezrin/Radixin/Moesin (ERM) proteins and class I myosins. Although the role of D3-phosphoinositides, such as PI(3,4,5)P₃, in actin-driven cell migration has been a subject of controversy, it becomes evident that the dynamic turnover of the phosphoinositide by the action of metabolizing enzymes, such as 5-phosphatases, is necessary. Recent studies have revealed an important role of PI(3,4)P₂in podosome/invadopodia formation, shedding new light on the actin-based organization of membrane structures regulated by phosphoinositide signaling. This article is part of a Special Issue entitled Phosphoinositides.Corresponding, Jun. 2015, Biochimica et biophysica acta, 1851(6) (6), 824 - 31, English, International magazine[Refereed]Scientific journal
- Lead, Jun. 2015, Nature Cell Biology, 17(6) (6), 749 - +, English, International magazine[Refereed]Scientific journal
- Lead, May 2013, Journal of Cell Science, 126(10) (10), 2267 - 2278, English, International magazine[Refereed]Scientific journal
- Jan. 2013, LANGMUIR, 29(1) (1), 328 - 336, English, International magazine[Refereed]Scientific journal
- Jul. 2012, Molecular Biology of the Cell, 23(13) (13), 2481 - 2489, English, International magazine[Refereed]Scientific journal
- Aug. 2011, Genes to Cells, 16(8) (8), 868 - 878, English, International magazine[Refereed]Scientific journal
- May 2011, Journal of Cell Biology, 193(5) (5), 901 - 916, English, International magazine[Refereed]Scientific journal
- Dec. 2010, Science, 330(6010) (6010), 1536 - 1540, English, International magazine[Refereed]Scientific journal
- Lead, Feb. 2010, Journal of Biological Chemistry, 285(9) (9), 6781 - 6789, English, International magazine[Refereed]Scientific journal
- Sep. 2009, Science Signaling, 2(87) (87), ra52, English, International magazine[Refereed]Scientific journal
- SGIP1alpha is an endocytic protein that directly interacts with phospholipids and Eps15.SGIP1 has been shown to be an endophilin-interacting protein that regulates energy balance, but its function is not fully understood. Here, we identified its splicing variant of SGIP1 and named it SGIP1alpha. SGIP1alpha bound to phosphatidylserine and phosphoinositides and deformed the plasma membrane and liposomes into narrow tubules, suggesting the involvement in vesicle formation during endocytosis. SGIP1alpha furthermore bound to Eps15, an important adaptor protein of clathrin-mediated endocytic machinery. SGIP1alpha was colocalized with Eps15 and the AP-2 complex. Upon epidermal growth factor (EGF) stimulation, SGIP1alpha was colocalized with EGF at the plasma membrane, indicating the localization of SGIP1alpha at clathrin-coated pits/vesicles. SGIP1alpha overexpression reduced transferrin and EGF endocytosis. SGIP1alpha knockdown reduced transferrin endocytosis but not EGF endocytosis; this difference may be due to the presence of redundant pathways in EGF endocytosis. These results suggest that SGIP1alpha plays an essential role in clathrin-mediated endocytosis by interacting with phospholipids and Eps15.Sep. 2009, Journal of Biological Chemistry, 282(36) (36), 26481 - 9, English, International magazine[Refereed]Scientific journal
- Lead, May 2007, Cell, 129(4) (4), 761 - 772, English, International magazine[Refereed]Scientific journal
- Aug. 2006, ANALYTICAL BIOCHEMISTRY, 355(1) (1), 8 - 18, English, International magazine[Refereed]Scientific journal
- Apr. 2006, Journal of Biochemistry, 139(4) (4), 663 - 670, English, International magazine[Refereed]Scientific journal
- Lead, Jan. 2006, Journal of Cell Biology, 172(2) (2), 269 - 279, English, International magazineCoordination between the actin cytoskeleton and membrane deformation by a novel membrane tubulation domain of PCH proteins is involved in endocytosis[Refereed]Scientific journal
- Lead, Apr. 2004, Journal of Biological Chemistry, 279(14) (14), 13817 - 13824, English, International magazine[Refereed]Scientific journal
- 2024, 日本生化学会大会(Web), 97thDA-Rafはリン脂質とRasの両方に結合することでRas-ERK経路と細胞遊走の向きを制御する
- 2022, 日本血管生物医学会学術集会プログラム・抄録集, 30th (CD-ROM)創傷治癒で起こる血管新生の新たな力学的制御機構:内腔圧がTOCAファミリーBARタンパク質を介して血管新生を制御する
- 2021, 日本細胞生物学会大会(Web), 73rdRegulation of Cell Membrane Tension by Membrane Curvature-Inducing Proteins
- 2021, 日本生化学会大会(Web), 94thDA-Rafは細胞膜と活性化Rasに結合することによりRas-ERK経路の全体的抑制因子として機能する
- (公社)日本生化学会, 2020, 日本生化学会大会(Web), 93rd, [3S06m - 01], Japanese血流に起因する内腔圧による創傷治癒過程の血管新生の新たな制御機構
- (公社)日本生化学会, 2020, 日本生化学会大会(Web), 93rd, [3S06a - 03], Japanese内腔圧の機械的刺激により制御される創傷治癒での血管新生
- 2020, 日本薬学会年会要旨集(CD-ROM), 140thCancer cell migration: Regulation of cancer cell migration by plasma membrane tension and membrane curvature-inducing proteins
- (一社)日本細胞生物学会, May 2017, 日本細胞生物学会大会講演要旨集, 69回, 134 - 134, JapaneseDA-Rafはリン脂質とRasの両方に結合することでRas-ERKカスケードを抑制する
- 日本発生生物学会・日本細胞生物学会, May 2007, 日本発生生物学会・日本細胞生物学会合同大会要旨集, 40回・59回, 15 - 15, EnglishPI3Kおよび関連シグナル伝達分子の機能 癌細胞におけるD3-ホスホイノシチドの定量化と視覚化のためのホスホイノシチド結合ドメインの利用(Use of phosphoinositide-binding domains for the quantification and visualization of D3-phosphoinositides in cancer cells)
- (公社)日本薬理学会, Feb. 2007, 日本薬理学雑誌, 129(2) (2), 42P - 42P, JapaneseSGIP1αによる膜輸送の制御
- ConBio2017, Dec. 2017, Japanese, 日本分子生物学会・日本生化学会, 神戸, Domestic conference細胞膜張力の恒常性制御機構[Invited]Invited oral presentation
- 第55回生物物理学会シンポジウム, Sep. 2017, English, 日本生物物理学会, 熊本, Domestic conferenceRole of plasma membrane tension in cell migration and invasion[Invited]Invited oral presentation
- メカノバイオロジー機構の解明による革新的医療機器及び医療技術の創出 平成27年度キックオフミーティング, Feb. 2016, Japanese, AMED, 東京, Domestic conference癌細胞の浸潤・転移を司る細胞膜の張力を介したシグナル伝達機構の解明[Invited]Nominated symposium
- 第88回日本生化学会ワークショップ, Dec. 2015, Japanese, 日本生化学会, 神戸, Domestic conferenceリン脂質結合タンパク質を介した細胞膜張力のシグナリング[Invited]Nominated symposium
- 第38回日本分子生物学会年会、第88回日本生化学会大会合同大会, Dec. 2015, Japanese, 日本生化学会・日本分子生物学会, 神戸, Domestic conferenceMembrane Tension Signaling Mediated by Lipid-binding ProteinsOral presentation
- The26th CDB Meeting, Sep. 2015, English, 理研CDB, 神戸, Domestic conferenceFeedback regulation between plasma membrane tension and membrane-bending proteins in cell migrationPublic symposium
- 第67回日本細胞生物学会, Jul. 2015, Japanese, 日本細胞生物学会, 東京, Domestic conference細胞運動時の極性形成における細胞膜の張力と膜変形タンパク質のフィードバック調節機構Public symposium
- 大阪大学微生物病研究所セミナー, Jun. 2015, Japanese, 大阪大学, 大阪, Domestic conference細胞運動における細胞膜の張力と膜変形タンパク質によるフィードバック制御機構[Invited]Invited oral presentation
- 第87回日本生化学会大会, Oct. 2014, Japanese, 日本生化学会, 京都, Domestic conferenceF-BARドメインタンパク質による細胞運動の制御Oral presentation
- 第56回日本脂質生化学会, Jun. 2014, Japanese, 日本脂質生化学会, 大阪, Domestic conference細胞質型チロシンキナーゼFerと生体膜との相互作用の解析Oral presentation
- 第56回日本脂質生化学会, Jun. 2014, Japanese, 日本脂質生化学会, 大阪, Domestic conferenceF-BARタンパク質による細胞膜の張力を介した極性形成機構Oral presentation
- 第82回生化学学会, Oct. 2009, Japanese, 日本生化学学会, 神戸, Domestic conferenceProteome of Acidic Phospholipid-binding Proteins: Spatial and Temporal Regulation of Coronin 1A by Phosphoinositides[Invited]Invited oral presentation
- THE JAPANESE CONFERENCE ON THE BIOCHEMISTRY OF LIPIDS
- JAPAN SOCIETY FOR CELL BIOLOGY
- THE JAPANESE BIOCHEMICAL SOCIETY
- 日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 01 Apr. 2025 - 31 Mar. 2028細胞老化における細胞膜張力の役割:膜力学マーカーの同定と機械的制御技術の確立
- 日本学術振興会, 科学研究費助成事業, 挑戦的研究(萌芽), 神戸大学, 28 Jun. 2024 - 31 Mar. 2026細胞膜張力をターゲットとしたがん免疫療法の開発
- 日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 01 Apr. 2023 - 31 Mar. 2026細胞膜メカニクスによるがん幹細胞性の機械的制御と新規治療戦略
- 日本学術振興会, 科学研究費助成事業 挑戦的研究(萌芽), 挑戦的研究(萌芽), 神戸大学, 30 Jun. 2022 - 31 Mar. 2024がん細胞の細胞膜張力を標的とした化合物の探索と治療法への応用
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Kobe University, 01 Apr. 2019 - 31 Mar. 2022Mechanism of Cell Membrane Tension Homeostasis by Membrane Tension Sensor ProteinsThis study focused on BAR proteins that induce and sense membrane curvature to elucidate the molecular mechanisms by which plasma membrane tension homeostasis is maintained in epithelial cells. Using a combination of optical tweezers and gene knockdown experiments, we identified a BAR protein X that is required for homeostasis of plasma membrane tension. We found that, X, which has a GAP domain for Rac, recruit to the membrane by sensing decreased membrane tension, where it inactive Rac, which in turn activates its competitor, RhoA. This RhoA activation seems to lead to increased membrane tension by increasing membrane-cortex attachment. These results suggest that a feedback regulation between plasma membrane tension and BAR protein X plays an important role in tensional homeostasis of the plasma membrane.
- 学術研究助成基金助成金/挑戦的萌芽研究, Apr. 2016 - Mar. 2018, Principal investigatorCompetitive research funding
- 国立研究開発法人日本医療研究開発機構, 革新的先端研究開発支援事業ソロタイプ「メカノバイオロジー機構の解明による革新的医療機器及び医療技術の創出」」研究開発領域, 2017, Principal investigator【AMED】癌細胞の浸潤・転移を司る細胞膜の張力を介したシグナル伝達機構の解明Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (S), Kobe University, 01 Apr. 2011 - 31 Mar. 2016Regulation of cell dynamism by phosphoinositidesPhosphoinositides act as crucial lipids to regulate versatile functions in life. Phosphoinositide-binding proteins, FBP17, PSTPIP2, SH3YL1 and ARAP1 recognize and bind membrane curvature, resulting in membrane deformation, such as coated pits and vesiculation of membrane. PI(3,4,5)P3 5-phosphatase SKIP binds GRP78 in endoplasmic reticulum under resting condition. But in response to insulin, it moves to membranes where it associates with Pak1 and hydrolyses PI(3,4,5)P3 spatio-temporaly around insulin receptors. Sac1 PI4P 4-phosphatase controls the PI4P concentration in Golgi, which is involved in cell adhesion and tumor metastasis.Thus, decrease in PI4P in Golgi prevents the invasion and metastasis of cancer cells.
- 学術研究助成基金助成金/基盤研究(C), Apr. 2013 - Mar. 2016, Principal investigatorCompetitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Kobe University, 01 Apr. 2012 - 31 Mar. 2015Molecular mechanism of endocytosis by a novel membrane-bending domainIt was found that human SH3YL1, which contains a novel phosphoinositide-binding domain named the SYLF domain, is involved in endocytosis of epidermal growth factor receptor. In vitro, SH3YL1 not only bound to liposomes, but also mediated interactions between liposomes that it resides, promoting aggregation of membrane vesicles. This study also succeeded in obtaining a knowledge about the positively-charged residues in the SYLF domain that participate in lipid-binding, therefore will provide a novel molecular basis of endocytosis.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), Kobe University, 2011 - 2012, Principal investigatorBy performing in vitro analysis, we directly showed the mechanism by which FBP17 regulates actin polymerization on the membrane tubules. Physiologically, it was found that FBP17 is recruited to phagocytic cup via its F-BAR domain and that this accumulation is critical for phagocytic cup formation. Furthermore, RNAi and its rescue experiments revealed that the assembly of FBP17 at the plasma membrane is dependent on its F-BAR domain, promoting actin polymerization at phagocytic cup membrane. These data suggest that invaginated membrane caused by FBP17 may function as a scaffold for actin polymerization.Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), Kobe University, 2008 - 2009, Principal investigatorIt was shown that PSTPIP2 is a negative regulator of phagocytosis. It is suggested that PSTPIP2 is localized to the nascent cup, where it suppress the robust actin polymerization. The localization of PSTPIP2 to the nascent cup is dependent on its lipid binding ability. In addition, PSTPIP2 is tyrosine phosphorylated following phagocytosis and its phosphorylation dissociates it from the nascent cup. Thus, PSTPIP2 is the novel negative regulator of phagocytosis though inhibiting phagocytic cup formation that is controlled by its tyrosine phosphorylation.Competitive research funding
