scholarly journals Direct signaling by the BMP type II receptor via the cytoskeletal regulator LIMK1

2003 ◽  
Vol 162 (6) ◽  
pp. 1089-1098 ◽  
Author(s):  
Victoria C. Foletta ◽  
Mei Ann Lim ◽  
Juliana Soosairajah ◽  
April P. Kelly ◽  
Edouard G. Stanley ◽  
...  

Bone morphogenetic proteins (BMPs) regulate multiple cellular processes, including cell differentiation and migration. Their signals are transduced by the kinase receptors BMPR-I and BMPR-II, leading to Smad transcription factor activation via BMPR-I. LIM kinase (LIMK) 1 is a key regulator of actin dynamics as it phosphorylates and inactivates cofilin, an actin depolymerizing factor. During a search for LIMK1-interacting proteins, we isolated clones encompassing the tail region of BMPR-II. Although the BMPR-II tail is not involved in BMP signaling via Smad proteins, mutations truncating this domain are present in patients with primary pulmonary hypertension (PPH). Further analysis revealed that the interaction between LIMK1 and BMPR-II inhibited LIMK1's ability to phosphorylate cofilin, which could then be alleviated by addition of BMP4. A BMPR-II mutant containing the smallest COOH-terminal truncation described in PPH failed to bind or inhibit LIMK1. This study identifies the first function of the BMPR-II tail domain and suggests that the deregulation of actin dynamics may contribute to the etiology of PPH.

2018 ◽  
Author(s):  
Juliana Antonipillai ◽  
Sheena Rigby ◽  
Nicole Bassler ◽  
Karlheinz Peter ◽  
Ora Bernard

AbstractActin is highly abundant in platelets, and platelet function is dependent on actin structures. Actin filaments are dynamic structures involved in many cellular processes including platelet shape changes and adhesion. The actin cytoskeleton is tightly regulated by actin-binding proteins, which include the members of the actin depolymerising factor (ADF)/cofilin family. LIM kinase (LIMK) and slingshot phosphatase (SSH-1L) regulate actin dynamics by controlling the binding affinity of ADF/cofilin towards actin. We hypothesised that inhibition of LIMK activity may prevent the changes in platelet shape during their activation and therefore their function by controlling the dynamics of Factin. Therefore, inhibition of LIMK activity may represent an attractive new strategy to control and inhibit platelet function; particularly the formation of stable platelet aggregates and thus stable thrombi.


Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Bing Zhao ◽  
Ye-Guang Chen

Transforming growth factor-β(TGF-β) signaling regulates diverse cellular processes, including cell proliferation, differentiation, apoptosis, cell plasticity, and migration. TGF-βsignaling can be mediated by Smad proteins or other signaling proteins such as MAP kinases and Akt. TGF-βsignaling is tightly regulated at different levels along the pathways to ensure its proper physiological functions in different cells and tissues. Deregulation of TGF-βsignaling has been associated with various kinds of diseases, such as cancer and tissue fibrosis. This paper focuses on our recent work on regulation of TGF-βsignaling.


2002 ◽  
Vol 13 (4) ◽  
pp. 1215-1226 ◽  
Author(s):  
Jayesh C. Patel ◽  
Alan Hall ◽  
Emmanuelle Caron

Phagocytosis is the process whereby cells direct the spatially localized, receptor-driven engulfment of particulate materials. It proceeds via remodeling of the actin cytoskeleton and shares many of the core cytoskeletal components involved in adhesion and migration. Small GTPases of the Rho family have been widely implicated in coordinating actin dynamics in response to extracellular signals and during diverse cellular processes, including phagocytosis, yet the mechanisms controlling their recruitment and activation are not known. We show herein that in response to ligation of Fc receptors for IgG (FcγR), the guanine nucleotide exchange factor Vav translocates to nascent phagosomes and catalyzes GTP loading on Rac, but not Cdc42. The Vav-induced Rac activation proceeds independently of Cdc42 function, suggesting distinct roles for each GTPase during engulfment. Moreover, inhibition of Vav exchange activity or of Cdc42 activity does not prevent Rac recruitment to sites of particle attachment. We conclude that Rac is recruited to Fcγ membrane receptors in its inactive, GDP-bound state and that Vav regulates phagocytosis through subsequent catalysis of GDP/GTP exchange on Rac.


2020 ◽  
Vol 21 (13) ◽  
pp. 4764
Author(s):  
Nanju Park ◽  
Hara Kang

Proliferation and migration of vascular smooth muscle cells (VSMCs) are implicated in blood vessel development, maintenance of vascular homeostasis, and pathogenesis of vascular disorders. MicroRNAs (miRNAs) mediate the regulation of VSMC functions in response to microenvironmental signals. Because a previous study reported that miR-101, a tumor-suppressive miRNA, is a critical regulator of cell proliferation in vascular disease, we hypothesized that miR-101 controls important cellular processes in VSMCs. The present study aimed to elucidate the effects of miR-101 on VSMC function and its molecular mechanisms. We revealed that miR-101 regulates VSMC proliferation and migration. We showed that miR-101 expression is induced by bone morphogenetic protein (BMP) signaling, and we identified dedicator of cytokinesis 4 (DOCK4) as a novel target of miR-101. Our results suggest that the BMP–miR-101–DOCK4 axis mediates the regulation of VSMC function. Our findings help further the understanding of vascular physiology and pathology.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Zhang ◽  
Zhaohui Zhong ◽  
Mei Li ◽  
Jingyi Chen ◽  
Tingru Lin ◽  
...  

AbstractAbnormally expressed and/or phosphorylated Abelson interactor 1 (ABI1) participates in the metastasis and progression of colorectal cancer (CRC). ABI1 presents as at least 12 transcript variants (TSVs) by mRNA alternative splicing, but it is unknown which of them is involved in CRC metastasis and prognosis. Here, we firstly identified ABI1-TSV-11 as a key TSV affecting the metastasis and prognosis of left-sided colorectal cancer (LsCC) and its elevated expression is related to lymph node metastasis and shorter overall survival (OS) in LsCC by analyzing data from The Cancer Genome Atlas and TSVdb. Secondly, ABI1-TSV-11 overexpression promoted LoVo and SW480 cells adhesion and migration in vitro, and accelerated LoVo and SW480 cells lung metastasis in vivo. Finally, mechanism investigations revealed that ABI1-isoform-11 interacted with epidermal growth factor receptor pathway substrate 8 (ESP8) and regulated actin dynamics to affect LoVo and SW480 cells biological behaviors. Taken together, our data demonstrated that ABI1-TSV-11 plays an oncogenic role in LsCC, it is an independent risk factor of prognosis and may be a potential molecular marker and therapeutic target in LsCC.


2021 ◽  
Vol 9 (3) ◽  
pp. 24
Author(s):  
Brian Heubel ◽  
Anja Nohe

The osteogenic effects of Bone Morphogenetic Proteins (BMPs) were delineated in 1965 when Urist et al. showed that BMPs could induce ectopic bone formation. In subsequent decades, the effects of BMPs on bone formation and maintenance were established. BMPs induce proliferation in osteoprogenitor cells and increase mineralization activity in osteoblasts. The role of BMPs in bone homeostasis and repair led to the approval of BMP2 by the Federal Drug Administration (FDA) for anterior lumbar interbody fusion (ALIF) to increase the bone formation in the treated area. However, the use of BMP2 for treatment of degenerative bone diseases such as osteoporosis is still uncertain as patients treated with BMP2 results in the stimulation of not only osteoblast mineralization, but also osteoclast absorption, leading to early bone graft subsidence. The increase in absorption activity is the result of direct stimulation of osteoclasts by BMP2 working synergistically with the RANK signaling pathway. The dual effect of BMPs on bone resorption and mineralization highlights the essential role of BMP-signaling in bone homeostasis, making it a putative therapeutic target for diseases like osteoporosis. Before the BMP pathway can be utilized in the treatment of osteoporosis a better understanding of how BMP-signaling regulates osteoclasts must be established.


2021 ◽  
pp. 1-12
Author(s):  
Pengli Wang ◽  
Dan Zheng ◽  
Hongyang Qi ◽  
Qi Gao

BACKGROUND: MicroRNAs (miRNAs) play potential role in the development of various types of cancer conditions including pancreatic cancer (PC) targeting several cellular processes. Present study was aimed to evaluate function of miR-125b and the mechanism involved in PC. METHODS: Cell migration, MTT and BrdU study was done to establish the migration capability, cell viability and cell proliferation respectively. Binding sites for miR-125b were recognized by luciferase assay, expression of protein by western blot and immunofluorescence assay. In vivo study was done by BALB/c nude xenograft mice for evaluating the function of miR-125b. RESULTS: The study showed that expression of miR-125b was elevated in PC cells and tissues, and was correlated to proliferation and migration of cells. Also, over-expression of miR-125b encouraged migration, metastasis and proliferation of BxPC-3 cells, the suppression reversed it. We also noticed that thioredoxin-interacting protein (TXNIP) was the potential target of miR-125b. The outcomes also suggested that miR-125b governed the expression of TXNIP inversely via directly attaching to the 3′-UTR activating hypoxia-inducible factor 1α (HIF1α). Looking into the relation between HIF1α and TXNIP, we discovered that TXNIP caused the degradation and export of HIF1α by making a complex with it. CONCLUSION: The miR-125b-TXNIP-HIF1α pathway may serve useful strategy for diagnosing and treating PC.


2021 ◽  
pp. 153537022110281
Author(s):  
Yu Hou ◽  
Yu-Xi He ◽  
Jia-Hao Zhang ◽  
Shu-Rong Wang ◽  
Yan Zhang

Epithelial tissue has important functions such as protection, secretion, and sensation. Epithelial damage is involved in various pathological processes. Bone morphogenetic proteins (BMPs) are a class of growth factors with multiple functions. They play important roles in epithelial cells, including in differentiation, proliferation, and migration during the repair of the epithelium. This article reviews the functions and mechanisms of the most profoundly studied BMPs in the process of epithelial damage repair and their clinical significance.


Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 593
Author(s):  
Khaled Elmasry ◽  
Samar Habib ◽  
Mohamed Moustafa ◽  
Mohamed Al-Shabrawey

Bone morphogenetic proteins (BMPs) play an important role in bone formation and repair. Recent studies underscored their essential role in the normal development of several organs and vascular homeostasis in health and diseases. Elevated levels of BMPs have been linked to the development of cardiovascular complications of diabetes mellitus. However, their particular role in the pathogenesis of microvascular dysfunction associated with diabetic retinopathy (DR) is still under-investigated. Accumulated evidence from our and others’ studies suggests the involvement of BMP signaling in retinal inflammation, hyperpermeability and pathological neovascularization in DR and age-related macular degeneration (AMD). Therefore, targeting BMP signaling in diabetes is proposed as a potential therapeutic strategy to halt the development of microvascular dysfunction in retinal diseases, particularly in DR. The goal of this review article is to discuss the biological functions of BMPs, their underlying mechanisms and their potential role in the pathogenesis of DR in particular.


2005 ◽  
Vol 16 (7) ◽  
pp. 3107-3116 ◽  
Author(s):  
Anindya Ghosh-Roy ◽  
Bela S. Desai ◽  
Krishanu Ray

Toward the end of spermiogenesis, spermatid nuclei are compacted and the clonally related spermatids individualize to become mature and active sperm. Studies in Drosophila showed that caudal end-directed movement of a microfilament-rich structure, called investment cone, expels the cytoplasmic contents of individual spermatids. F-actin dynamics plays an important role in this process. Here we report that the dynein light chain 1 (DLC1) of Drosophila is involved in two separate cellular processes during sperm individualization. It is enriched around spermatid nuclei during postelongation stages and plays an important role in the dynein-dynactin–dependent rostral retention of the nuclei during this period. In addition, DDLC1 colocalizes with dynamin along investment cones and regulates F-actin assembly at this organelle by retaining dynamin along the cones. Interestingly, we found that this process does not require the other subunits of cytoplasmic dynein-dynactin complex. Altogether, these observations suggest that DLC1 could independently regulate multiple cellular functions and established a novel role of this protein in F-actin assembly in Drosophila.


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