1
|
Nahalka J. Theoretical Analysis of S, M and N Structural Proteins by the Protein-RNA Recognition Code Leads to Genes/proteins that Are Relevant to the SARS-CoV-2 Life Cycle and Pathogenesis. Front Genet 2021; 12:763995. [PMID: 34659373 PMCID: PMC8511677 DOI: 10.3389/fgene.2021.763995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
In this conceptual review, based on the protein-RNA recognition code, some theoretical sequences were detected in the spike (S), membrane (M) and capsid (N) proteins that may post-transcriptionally regulate the host genes/proteins in immune homeostasis, pulmonary epithelial tissue homeostasis, and lipid homeostasis. According to the review of literature, the spectrum of identified genes/proteins shows that the virus promotes IL1α/β-IL1R1 signaling (type 1 immunity) and immunity defense against helminths and venoms (type 2 immunity). In the alteration of homeostasis in the pulmonary epithelial tissue, the virus blocks the function of cilia and the molecular programs that are involved in wound healing (EMT and MET). Additionally, the protein-RNA recognition method described here identifies compatible sequences in the S1A-domain for the post-transcriptional promotion of PIKFYVE, which is one of the critical factors for SARS-CoV-2 entry to the host cell, and for the post-transcriptional repression of xylulokinase XYLB. A decrease in XYLB product (Xu5P) in plasma was proposed as one of the potential metabolomics biomarkers of COVID-19. In summary, the protein-RNA recognition code leads to protein genes relevant to the SARS-CoV-2 life cycle and pathogenesis.
Collapse
Affiliation(s)
- Jozef Nahalka
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Bratislava, Slovakia
- Institute of Chemistry, Centre of Excellence for White-green Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia
| |
Collapse
|
2
|
Lee M, Betz C, Yin J, Paatero I, Schellinx N, Carte AN, Wilson CW, Ye W, Affolter M, Belting HG. Control of dynamic cell behaviors during angiogenesis and anastomosis by Rasip1. Development 2021; 148:271819. [PMID: 34383884 PMCID: PMC8380458 DOI: 10.1242/dev.197509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 06/08/2021] [Indexed: 11/23/2022]
Abstract
Organ morphogenesis is driven by a wealth of tightly orchestrated cellular behaviors, which ensure proper organ assembly and function. Many of these cell activities involve cell-cell interactions and remodeling of the F-actin cytoskeleton. Here, we analyze the requirement for Rasip1 (Ras-interacting protein 1), an endothelial-specific regulator of junctional dynamics, during blood vessel formation. Phenotype analysis of rasip1 mutants in zebrafish embryos reveals distinct functions of Rasip1 during sprouting angiogenesis, anastomosis and lumen formation. During angiogenic sprouting, loss of Rasip1 causes cell pairing defects due to a destabilization of tricellular junctions, indicating that stable tricellular junctions are essential to maintain multicellular organization within the sprout. During anastomosis, Rasip1 is required to establish a stable apical membrane compartment; rasip1 mutants display ectopic, reticulated junctions and the apical compartment is frequently collapsed. Loss of Ccm1 and Heg1 function mimics the junctional defects of rasip1 mutants. Furthermore, downregulation of ccm1 and heg1 leads to a delocalization of Rasip1 at cell junctions, indicating that junctional tethering of Rasip1 is required for its function in junction formation and stabilization during sprouting angiogenesis. Summary:In vivo analysis of rasip1 mutants reveals multiple roles for Rasip1 during angiogenic sprouting, anastomosis and lumen formation, including stabilization of tricellular junctions to permit coordinated cell rearrangements and multicellular tube formation.
Collapse
Affiliation(s)
- Minkyoung Lee
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Charles Betz
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Jianmin Yin
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Ilkka Paatero
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Niels Schellinx
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Adam N Carte
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Christopher W Wilson
- Department of Molecular Biology, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Weilan Ye
- Department of Molecular Biology, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Markus Affolter
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | - Heinz-Georg Belting
- Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| |
Collapse
|
3
|
Phng LK, Belting HG. Endothelial cell mechanics and blood flow forces in vascular morphogenesis. Semin Cell Dev Biol 2021; 120:32-43. [PMID: 34154883 DOI: 10.1016/j.semcdb.2021.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/10/2021] [Accepted: 06/10/2021] [Indexed: 12/21/2022]
Abstract
The vertebrate cardiovascular system is made up by a hierarchically structured network of highly specialised blood vessels. This network emerges during early embryogenesis and evolves in size and complexity concomitant with embryonic growth and organ formation. Underlying this plasticity are actin-driven endothelial cell behaviours, which allow endothelial cells to change their shape and move within the vascular network. In this review, we discuss the cellular and molecular mechanisms involved in vascular network formation and how these intrinsic mechanisms are influenced by haemodynamic forces provided by pressurized blood flow. While most of this review focusses on in vivo evidence from zebrafish embryos, we also mention complementary findings obtained in other experimental systems.
Collapse
Affiliation(s)
- Li-Kun Phng
- Laboratory for Vascular Morphogenesis, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan.
| | - Heinz-Georg Belting
- Department of Cell Biology, Biozentrum, University of Basel, Basel 4056, Switzerland.
| |
Collapse
|
4
|
Lopez-Ramirez MA, McCurdy S, Li W, Haynes MK, Hale P, Francisco K, Oukoloff K, Bautista M, Choi CHJ, Sun H, Gongol B, Shyy JY, Ballatore C, Sklar LA, Gingras AR. Inhibition of the HEG1-KRIT1 interaction increases KLF4 and KLF2 expression in endothelial cells. FASEB Bioadv 2021; 3:334-355. [PMID: 33977234 PMCID: PMC8103725 DOI: 10.1096/fba.2020-00141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/29/2021] [Indexed: 11/11/2022] Open
Abstract
The transmembrane protein heart of glass1 (HEG1) directly binds to and recruits Krev interaction trapped protein 1 (KRIT1) to endothelial junctions to form the HEG1-KRIT1 protein complex that establishes and maintains junctional integrity. Genetic inactivation or knockdown of endothelial HEG1 or KRIT1 leads to the upregulation of transcription factors Krüppel-like factors 4 and 2 (KLF4 and KLF2), which are implicated in endothelial vascular homeostasis; however, the effect of acute inhibition of the HEG1-KRIT1 interaction remains incompletely understood. Here, we report a high-throughput screening assay and molecular design of a small-molecule HEG1-KRIT1 inhibitor to uncover acute changes in signaling pathways downstream of the HEG1-KRIT1 protein complex disruption. The small-molecule HEG1-KRIT1 inhibitor 2 (HKi2) was demonstrated to be a bona fide inhibitor of the interaction between HEG1 and KRIT1 proteins, by competing orthosterically with HEG1 through covalent reversible interactions with the FERM (4.1, ezrin, radixin, and moesin) domain of KRIT1. The crystal structure of HKi2 bound to KRIT1 FERM revealed that it occupies the same binding pocket on KRIT1 as the HEG1 cytoplasmic tail. In human endothelial cells (ECs), acute inhibition of the HEG1-KRIT1 interaction by HKi2 increased KLF4 and KLF2 mRNA and protein levels, whereas a structurally similar inactive compound failed to do so. In zebrafish, HKi2 induced expression of klf2a in arterial and venous endothelium. Furthermore, genome-wide RNA transcriptome analysis of HKi2-treated ECs under static conditions revealed that, in addition to elevating KLF4 and KLF2 expression, inhibition of the HEG1-KRIT1 interaction mimics many of the transcriptional effects of laminar blood flow. Furthermore, HKi2-treated ECs also triggered Akt signaling in a phosphoinositide 3-kinase (PI3K)-dependent manner, as blocking PI3K activity blunted the Akt phosphorylation induced by HKi2. Finally, using an in vitro colocalization assay, we show that HKi6, an improved derivative of HKi2 with higher affinity for KRIT1, significantly impedes recruitment of KRIT1 to mitochondria-localized HEG1 in CHO cells, indicating a direct inhibition of the HEG1-KRIT1 interaction. Thus, our results demonstrate that early events of the acute inhibition of HEG1-KRIT1 interaction with HKi small-molecule inhibitors lead to: (i) elevated KLF4 and KLF2 gene expression; and (ii) increased Akt phosphorylation. Thus, HKi's provide new pharmacologic tools to study acute inhibition of the HEG1-KRIT1 protein complex and may provide insights to dissect early signaling events that regulate vascular homeostasis.
Collapse
Affiliation(s)
- Miguel Alejandro Lopez-Ramirez
- Department of Medicine University of California San Diego La Jolla CA USA.,Department of Pharmacology University of California San Diego La Jolla CA USA
| | - Sara McCurdy
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Wenqing Li
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Mark K Haynes
- Department of Pathology Center for Molecular Discovery University of New Mexico School of Medicine Albuquerque NM USA
| | - Preston Hale
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Karol Francisco
- Department of Chemistry & Biochemistry University of California San Diego La Jolla CA USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences University of California San Diego La Jolla CA USA
| | - Killian Oukoloff
- Skaggs School of Pharmacy and Pharmaceutical Sciences University of California San Diego La Jolla CA USA
| | - Matthew Bautista
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Chelsea H J Choi
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Hao Sun
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Brendan Gongol
- Department of Medicine University of California San Diego La Jolla CA USA
| | - John Y Shyy
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Carlo Ballatore
- Skaggs School of Pharmacy and Pharmaceutical Sciences University of California San Diego La Jolla CA USA
| | - Larry A Sklar
- Department of Pathology Center for Molecular Discovery University of New Mexico School of Medicine Albuquerque NM USA
| | | |
Collapse
|
5
|
Choi BH, Kou Z, Colon TM, Chen CH, Chen Y, Dai W. Identification of Radil as a Ras binding partner and putative activator. J Biol Chem 2021; 296:100314. [PMID: 33482197 PMCID: PMC7949112 DOI: 10.1016/j.jbc.2021.100314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 12/30/2022] Open
Abstract
Ras genes are among the most frequently mutated oncogenes in human malignancies. To date, there are no successful anticancer drugs in the clinic that target Ras proteins or their pathways. Therefore, it is imperative to identify and characterize new components that regulate Ras activity or mediate its downstream signaling. To this end, we used a combination of affinity-pulldown and mass spectrometry to search for proteins that are physically associated with KRas. One of the top hits was Radil, a gene product with a Ras-association domain. Radil is known to be a downstream effector of Rap1, inhibiting RhoA signaling to regulate cell adhesion and migration. We demonstrate that Radil interacted with all three isoforms of Ras including HRas, NRas, and KRas, although it exhibited the strongest interaction with KRas. Moreover, Radil interacts with GTP-bound Ras more efficiently, suggesting a possibility that Radil may be involved in Ras activation. Supporting this, ectopic expression of Radil led to transient activation of mitogen-activated protein kinase kinase and extracellular signal-regulated kinase; Radil knockdown resulted in weakened activation of Ras downstream signaling components, which was coupled with decreased cell proliferation and invasion, and reduced expression of mesenchymal cell markers. Moreover, Radil knockdown greatly reduced the number of adhesion foci and depolymerized actin filaments, molecular processes that facilitate cancer cell migration. Taken together, our present studies strongly suggest that Radil is an important player for regulating Ras signaling, cell adhesion, and the epithelial–mesenchymal transition and may provide new directions for Ras-related anticancer drug development.
Collapse
Affiliation(s)
- Byeong Hyeok Choi
- Department of Environmental Medicine, New York University Langone Medical Center, New York, New York, USA
| | - Ziyue Kou
- Department of Environmental Medicine, New York University Langone Medical Center, New York, New York, USA
| | - Tania Marlyn Colon
- Department of Environmental Medicine, New York University Langone Medical Center, New York, New York, USA
| | - Chih-Hong Chen
- Department of Surgery and Moores Cancer Center, UC San Diego Health, La Jolla, California, USA
| | - Yuan Chen
- Department of Surgery and Moores Cancer Center, UC San Diego Health, La Jolla, California, USA
| | - Wei Dai
- Department of Environmental Medicine, New York University Langone Medical Center, New York, New York, USA; Department of Biochemistry and Molecular Pharmacology, New York University Langone Medical Center, New York, New York, USA.
| |
Collapse
|
6
|
Sigaroodi F, Shafaei H, Karimipour M, Dolatkhah MA, Delazar A. Aloe Vera/Collagen Mixture Induces Integrin α1β1 and PECAM-1 Genes Expression in Human Adipose-Derived Stem Cells. Adv Pharm Bull 2019; 9:662-667. [PMID: 31857972 PMCID: PMC6912176 DOI: 10.15171/apb.2019.077] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/06/2019] [Accepted: 06/15/2019] [Indexed: 12/25/2022] Open
Abstract
Purpose: Natural biomaterials are a key base in tissue engineering, and collagen, as the main content of the extracellular matrix (ECM), is frequently used in tissue engineering. Aloe vera has some therapeutic effects on ulcers, therefore, the use of this natural resource has always been considered for improving collagen function. We aimed to evaluate the effect of Aloe vera/ Collagen blended on cell viability, cell attachment, and angiogenic potential by determining of integrin α1β1 and platelet endothelial cell adhesion molecule (PECAM-1) genes expression in human adipose-derived stem cells (hASCs). Methods: In this study, hASCs after harvesting of adipose tissues from abdominal subcutaneous adipose tissue and isolation, were cultured in four groups of control, collagen gel, Aloe vera gel, and Aloe vera/collagen blended in vitro environment at 24h and then cell viability was assessed by MTT (3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium) assay. Integrin α1β1 and PECAM-1 genes expression were evaluated by real-time RT-PCR. Results: The results of MTT showed that the combination of Aloe vera/collagen was retained the cell viability at the normal range and improved it. In real-time RT-PCR results, integrin α1β1 and PECAM-1 gene expression were increased in the Aloe vera/collagen blended group compared to the control group. Conclusion: For tissue engineering purposes, Aloe vera improves collagen properties in the culture of hASCs by increasing the expression of the integrin α1β1 and PECAM-1 genes.
Collapse
Affiliation(s)
- Faraz Sigaroodi
- Stem Cells Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hajar Shafaei
- Stem Cells Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Karimipour
- Stem Cells Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Amin Dolatkhah
- Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Abbas Delazar
- Faculty of Pharmacy and Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
7
|
Gingras AR, Lagarrigue F, Cuevas MN, Valadez AJ, Zorovich M, McLaughlin W, Lopez-Ramirez MA, Seban N, Ley K, Kiosses WB, Ginsberg MH. Rap1 binding and a lipid-dependent helix in talin F1 domain promote integrin activation in tandem. J Cell Biol 2019; 218:1799-1809. [PMID: 30988001 PMCID: PMC6548133 DOI: 10.1083/jcb.201810061] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/11/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023] Open
Abstract
Rap1 GTPases bind effectors, such as RIAM, to enable talin1 to induce integrin activation. In addition, Rap1 binds directly to the talin1 F0 domain (F0); however, this interaction makes a limited contribution to integrin activation in CHO cells or platelets. Here, we show that talin1 F1 domain (F1) contains a previously undetected Rap1-binding site of similar affinity to that in F0. A structure-guided point mutant (R118E) in F1, which blocks Rap1 binding, abolishes the capacity of Rap1 to potentiate talin1-induced integrin activation. The capacity of F1 to mediate Rap1-dependent integrin activation depends on a unique loop in F1 that has a propensity to form a helix upon binding to membrane lipids. Basic membrane-facing residues of this helix are critical, as charge-reversal mutations led to dramatic suppression of talin1-dependent activation. Thus, a novel Rap1-binding site and a transient lipid-dependent helix in F1 work in tandem to enable a direct Rap1-talin1 interaction to cause integrin activation.
Collapse
Affiliation(s)
| | | | - Monica N Cuevas
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Andrew J Valadez
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Marcus Zorovich
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wilma McLaughlin
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | | | - Nicolas Seban
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Immunology, La Jolla, CA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA
| | - William B Kiosses
- Microscopy Core Facility, La Jolla Institute for Immunology, La Jolla, CA
| | - Mark H Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, CA
| |
Collapse
|
8
|
Lagarrigue F, Gingras AR, Paul DS, Valadez AJ, Cuevas MN, Sun H, Lopez-Ramirez MA, Goult BT, Shattil SJ, Bergmeier W, Ginsberg MH. Rap1 binding to the talin 1 F0 domain makes a minimal contribution to murine platelet GPIIb-IIIa activation. Blood Adv 2018; 2:2358-2368. [PMID: 30242097 PMCID: PMC6156890 DOI: 10.1182/bloodadvances.2018020487] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/11/2018] [Indexed: 01/08/2023] Open
Abstract
Activation of platelet glycoprotein IIb-IIIa (GPIIb-IIIa; integrin αIIbβ3) leads to high-affinity fibrinogen binding and platelet aggregation during hemostasis. Whereas GTP-bound Rap1 GTPase promotes talin 1 binding to the β3 cytoplasmic domain to activate platelet GPIIb-IIIa, the Rap1 effector that regulates talin association with β3 in platelets is unknown. Rap1 binding to the talin 1 F0 subdomain was proposed to forge the talin 1-Rap1 link in platelets. Here, we report a talin 1 point mutant (R35E) that significantly reduces Rap1 affinity without a significant effect on its structure or expression. Talin 1 head domain (THD) (R35E) was of similar potency to wild-type THD in activating αIIbβ3 in Chinese hamster ovary cells. Coexpression with activated Rap1b increased activation, and coexpression with Rap1GAP1 reduced activation caused by transfection of wild-type THD or THD(R35E). Furthermore, platelets from Tln1R35E/R35E mice showed similar GPIIb-IIIa activation to those from wild-type littermates in response to multiple agonists. Tln1R35E/R35E platelets exhibited slightly reduced platelet aggregation in response to low doses of agonists; however, there was not a significant hemostatic defect, as judged by tail bleeding times. Thus, the Rap1-talin 1 F0 interaction has little effect on platelet GPIIb-IIIa activation and hemostasis and cannot account for the dramatic effects of loss of Rap1 activity on these platelet functions.
Collapse
Affiliation(s)
| | | | - David S Paul
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Andrew J Valadez
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Monica N Cuevas
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Hao Sun
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | | | - Benjamin T Goult
- School of Biosciences, University of Kent, Kent, United Kingdom; and
| | - Sanford J Shattil
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wolfgang Bergmeier
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mark H Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, CA
| |
Collapse
|
9
|
Abstract
This review addresses the issue of the numerous roles played by Rap1 GTPase (guanosine triphosphatase) in different cell types, in terms of both physiology and pathology. It is one among a myriad of small G proteins with endogenous GTP-hydrolyzing activity that is considerably stimulated by posttranslational modifications (geranylgeranylation) or guanine nucleotide exchange factors (GEFs), and inhibited by GTPase-activating proteins (GAPs). Rap1 is a ubiquitous protein that plays an essential role in the control of metabolic processes, such as signal transduction from plasma membrane receptors, cytoskeleton rearrangements necessary for cell division, intracellular and substratum adhesion, as well as cell motility, which is needed for extravasation or fusion. We present several examples of how Rap1 affects cells and organs, pointing to possible molecular manipulations that could have application in the therapy of several diseases.
Collapse
|
10
|
Abstract
In this issue of Structure, Gingras et al. (2016) show that Ras association (RA) domains of the Rap1 and Ras interacting protein Rasip1 can form a dimer in the presence and absence of the small G protein Rap1. This provides an explanation for the observed complex formation in Rap1-mediated signaling.
Collapse
Affiliation(s)
- Holger Rehmann
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
| | - Johannes L Bos
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands.
| |
Collapse
|
11
|
Abstract
Maintenance and regulation of the vascular endothelial cell junctional complex is critical for proper barrier function of the blood-brain barrier (BBB) and the highly related blood-retinal barrier (BRB) that help maintain proper neuronal environment. Recent research has demonstrated that the junctional complex is actively maintained and can be dynamically regulated. Studies focusing on the mechanisms of barrier formation, maintenance, and barrier disruption have been of interest to understanding development of the BBB and BRB and identifying a means for therapeutic intervention for diseases ranging from brain tumors and dementia to blinding eye diseases. Research has increasingly revealed that small GTPases play a critical role in both barrier formation and disruption mechanisms. This review will summarize the current data on small GTPases in barrier regulation with an emphasis on the EPAC-Rap1 signaling pathway to Rho in endothelial barriers, as well as explore its potential involvement in paracellular flux and transcytosis regulation.
Collapse
Affiliation(s)
- Carla J Ramos
- a Department of Ophthalmology and Visual Sciences , University of Michigan , Ann Arbor , MI USA
| | - David A Antonetti
- a Department of Ophthalmology and Visual Sciences , University of Michigan , Ann Arbor , MI USA
| |
Collapse
|