Requirement for Coronin 1 in T Lymphocyte Trafficking and Cellular Homeostasis

Reversible interactions between acidic phospholipids in the cellular membrane and proteins in the cytosol play fundamental roles in a wide variety of physiological events. Here, we present a novel approach to the identification of acidic phospholipid-binding proteins using nano-liquid chromatography-tandem mass spectrometry. We found more than 400 proteins, including proteins with previously known acidic phospholipid-binding properties, and confirmed that several candidates, such as Coronin 1A, mDia1 (Diaphanous-related formin-1), PIR121/CYFIP2, EB2 (end plus binding protein-2), KIF21A (kinesin family member 21A), eEF1A1 (translation elongation factor 1␣1), and TRIM2, directly bind to acidic phospholipids. Among such novel proteins, we provide evidence that Coronin 1A activity, which disassembles Arp2/3-containing actin filament branches, is spatially and temporally regulated by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P 2 ). Whereas Coronin 1A co-localizes with PI(4,5)P 2 at the plasma membrane in resting cells, it is dissociated from the plasma membrane during lamellipodia formation where the PI(4,5)P 2 signal is significantly reduced. Our in vitro experiments show that Coronin 1A preferentially binds to PI(4,5)P 2 -containing liposomes and that PI(4,5)P 2 antagonizes the ability of Coronin 1A to disassemble actin filament branches, indicating a spatiotemporal regulation of Coronin 1A via a direct interaction with the plasma membrane lipid. Collectively, our proteomics data provide a list of potential acidic phospholipid-binding protein candidates ranging from the actin regulatory proteins to translational regulators.

Section: Discussionsupporting

confidence: 68%

Proteome of Acidic Phospholipid-binding Proteins

Tsujita

Itoh

Kondo

et al. 2010

“…An earlier study of coronin 1A knock-out mice reported that coronin 1A has an Arp2/3-5-dependent inhibitory effect on F-actin formation and concluded that coronin 1A is indispensable for TCR signaling (27,29). In the present study, overexpression of coronin 1A restored the proliferative response.…”

Section: Discussionsupporting

confidence: 66%

“…The Arp2/3 (actin-related protein 2/3) complex has been reported to be essential for TCR-mediated cytoskeletal reorganization (23,24), and Arp2/3 complex-mediated actin nucleation is required for the formation of an F-actin-rich lamellipod (22,25,26). Coronin 1A is preferentially expressed in hematopoietic cells and co-localizes with F-actin-rich membranes in activated T cells (27). Coronin 1A has been shown to bind the Arp2/3 complex and inhibit F-actin nucleation by freezing the Arp2/3 complex in its inactive conformation (28).…”

mentioning

confidence: 99%

GRAIL (Gene Related to Anergy in Lymphocytes) Regulates Cytoskeletal Reorganization through Ubiquitination and Degradation of Arp2/3 Subunit 5 and Coronin 1A

Ichikawa

Mizuno

Yamamura

et al. 2011

Anergy is an important mechanism for the maintenance of peripheral tolerance and avoidance of autoimmunity. The upregulation of E3 ubiqitin ligases, including GRAIL (gene related to anergy in lymphocytes), is a key event in the induction and preservation of anergy in T cells. However, the mechanisms of GRAIL-mediated anergy induction are still not completely understood. We examined which proteins serve as substrates for GRAIL in anergic T cells. Arp2/3-5 (actin-related protein 2/3 subunit 5) and coronin 1A were polyubiquitinated by GRAIL via Lys-48 and Lys-63 linkages. In anergic T cells and GRAIL-overexpressed T cells, the expression of Arp2/3-5 and coronin 1A was reduced. Furthermore, we demonstrated that GRAIL impaired lamellipodium formation and reduced the accumulation of F-actin at the immunological synapse. GRAIL functions via the ubiquitination and degradation of actin cytoskeletonassociated proteins, in particular Arp2/3-5 and coronin 1A. These data reveal that GRAIL regulates proteins involved in the actin cytoskeletal organization, thereby maintaining the unresponsive state of anergic T cells.

“…More recently, it was reported that the p57/coronin-1 gene was responsible for human and mouse severe combined immunodeficiency (22,23). In mice deficient in the p57/coronin-1 gene, differentiation and chemokine-mediated trafficking of T cells were severely impaired (22,24,25). It was further demonstrated that the developments of experimental autoimmune encephalomyelitis (26,27) and lupus-like autoimmune disease (28) were suppressed in mice with genetic defects of p57/coronin-1.…”

mentioning

confidence: 82%

“…8A). Indeed, it has been suggested that p57/coronin-1 physically interacts with the Arp 2/3 complex and that the interaction is weakened by the mutation at Ser-2 of p57/coronin-1 in lymphocytes (24,32); i.e. the wild-type and S2A mutant (in which Ser-2 was replaced with Ala) of p57/coronin-1 bound to the Arp 2/3 complex, whereas the phosphorylation mimic S2D (in which Ser-2 was replaced with Asp) exhibited decreased binding activity, suggesting the possible involvement of Ser-2 phosphorylation in the interaction between p57/coronin-1 and the Arp 2/3 complex.…”

Section: Discussionmentioning

confidence: 99%

Constitutive Turnover of Phosphorylation at Thr-412 of Human p57/Coronin-1 Regulates the Interaction with Actin

Oku

Nakano

Kaneko

et al. 2012

Background: Biological functions of actin-binding protein p57/coronin-1 may be regulated by phosphorylation. Results: Ser-2 and Thr-412 were identified as major phosphorylation sites of p57/coronin-1, and the phosphorylation at Thr-412 reduced the binding affinity for actin. Conclusion: Physical interaction between p57/coronin-1 and actin is regulated by phosphorylation at Thr-412. Significance: The results provide mechanistic insight into the actin-related immunological processes.