scholarly journals An Overview of the Primary Cilium and RPGRIP1L: The Signalling Hub’s Anchor for Organ Development and Homeostasis

2021 ◽  
Vol 17 (5) ◽  
pp. 582-592
Author(s):  
Ivanna Williantarra ◽  
Timmy Richardo ◽  
Inge Kumalasari Sudibjo ◽  
Putu Virgina Partha Devanthi

Research on the primary cilium has been growing exponentially in the past several decades due to its functions as a cell signalling hub, which defects leads to several disorders and abnormalities collectively known as ciliopathies. Among other parts of the primary cilium structures, the transition zone is the area whose defects lead to the most severe clinical manifestations and high lethality. The ciliary transition zone consists of multiple protein modules that are hypothesized to be anchored by the RPGRIP1L protein. Despite its importance, RPGRIP1L studies remain hidden from the limelight, and our understanding of the protein remains scattered. This review summarizes the clinical manifestations and molecular mechanisms of the RPGRIP1L in the primary cilium. We then take a closer look at each RPGRIP1L’s protein domain to understand how each domain ensures proper functions and localization of RPGRIP1L. The three domains of RPGRIP1L are postulated to be involved in different roles. While the coiled coil domain is vital for scaffolding the protein to the centriolar structure, the ability of the C2 domain to interact with lipid allows the formation of ‘lipid gate’ at the transition zone. The high variability of the RPGR interaction domain enable the RPGRIP1L to interact with multiple different proteins, making it an ideal anchor for other ciliary protein modules in the transition zone.

Author(s):  
Saleh A. Almatroodi ◽  
Mansoor Ali Syed ◽  
Arshad Husain Rahmani

Background:: Curcumin, an active compound of turmeric spice is one of the most-studies natural compounds and have been widely recognized as chemopreventive agents. Several molecular mechanisms have been proven, curcumin and its analogs play a role in cancer prevention through modulating various cell signaling pathways as well as inhibition of carcinogenesis process. Objective:: To study the potential role of curcumin in the management of various types of cancer through modulating cell signalling molecules based on available literature and recent patents. Methods:: A wide-ranging literature survey was performed based on Scopus, PubMed, PubMed central and Google scholar for the implication of curcumin in cancer management along with special emphasis on human clinical trials. Moreover, patents were searched through www.google.com/patents, www.freepatentsonline.com and www.freshpatents.com. Result:: Recent studies based on cancer cells have proven that curcumin have potential effects against cancer cells, prevent the growth of cancer and act as cancer therapeutic agents. Besides, curcumin exerted anticancer effects through inducing apoptosis, activating tumor suppressor genes, cell cycle arrest, inhibiting tumor angiogenesis, initiation, promotion and progression stages of tumor. It was established that co-treatment of curcumin and anti-cancer drugs could induce apoptosis and also play a significant role in the suppression of the invasion and metastasis of cancer cells. Conclusion:: Accumulating evidences suggest that curcumin has potentiality to inhibit cancer growth, induced apoptosis and modulate various cell signalling pathways molecules. Well-designed clinical trials of curcumin based on human subjects are still needed to establish the bioavailability, mechanism of action, efficacy and safe dose in the management of various cancers.


2007 ◽  
Vol 91 ◽  
pp. 119-119
Author(s):  
K Azibi ◽  
C Heltianu ◽  
C Caillaud ◽  
J Manicom ◽  
JP Puech ◽  
...  

Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 181
Author(s):  
Kun Qiao ◽  
Caiyun Jiang ◽  
Min Xu ◽  
Bei Chen ◽  
Wenhui Qiu ◽  
...  

The von Willebrand factor type D (VWD) domain in vitellogenin has recently been found to bind tetrodotoxin. The way in which this protein domain associates with tetrodotoxin and participates in transporting tetrodotoxin in vivo remains unclear. A cDNA fragment of the vitellogenin gene containing the VWD domain from pufferfish (Takifugu flavidus) (TfVWD) was cloned. Using in silico structural and docking analyses of the predicted protein, we determined that key amino acids (namely, Val115, ASP116, Val117, and Lys122) in TfVWD mediate its binding to tetrodotoxin, which was supported by in vitro surface plasmon resonance analysis. Moreover, incubating recombinant rTfVWD together with tetrodotoxin attenuated its toxicity in vivo, further supporting protein–toxin binding and indicating associated toxicity-neutralizing effects. Finally, the expression profiling of TfVWD across different tissues and developmental stages indicated that its distribution patterns mirrored those of tetrodotoxin, suggesting that TfVWD may be involved in tetrodotoxin transport in pufferfish. For the first time, this study reveals the amino acids that mediate the binding of TfVWD to tetrodotoxin and provides a basis for further exploration of the molecular mechanisms underlying the enrichment and transfer of tetrodotoxin in pufferfish.


2012 ◽  
Vol 442 (3) ◽  
pp. 453-464 ◽  
Author(s):  
Ashlee Higdon ◽  
Anne R. Diers ◽  
Joo Yeun Oh ◽  
Aimee Landar ◽  
Victor M. Darley-Usmar

The process of lipid peroxidation is widespread in biology and is mediated through both enzymatic and non-enzymatic pathways. A significant proportion of the oxidized lipid products are electrophilic in nature, the RLS (reactive lipid species), and react with cellular nucleophiles such as the amino acids cysteine, lysine and histidine. Cell signalling by electrophiles appears to be limited to the modification of cysteine residues in proteins, whereas non-specific toxic effects involve modification of other nucleophiles. RLS have been found to participate in several physiological pathways including resolution of inflammation, cell death and induction of cellular antioxidants through the modification of specific signalling proteins. The covalent modification of proteins endows some unique features to this signalling mechanism which we have termed the ‘covalent advantage’. For example, covalent modification of signalling proteins allows for the accumulation of a signal over time. The activation of cell signalling pathways by electrophiles is hierarchical and depends on a complex interaction of factors such as the intrinsic chemical reactivity of the electrophile, the intracellular domain to which it is exposed and steric factors. This introduces the concept of electrophilic signalling domains in which the production of the lipid electrophile is in close proximity to the thiol-containing signalling protein. In addition, we propose that the role of glutathione and associated enzymes is to insulate the signalling domain from uncontrolled electrophilic stress. The persistence of the signal is in turn regulated by the proteasomal pathway which may itself be subject to redox regulation by RLS. Cell death mediated by RLS is associated with bioenergetic dysfunction, and the damaged proteins are probably removed by the lysosome-autophagy pathway.


Blood ◽  
2008 ◽  
Vol 112 (12) ◽  
pp. 4384-4399 ◽  
Author(s):  
Elaine S. Jaffe ◽  
Nancy Lee Harris ◽  
Harald Stein ◽  
Peter G. Isaacson

AbstractIn the past 50 years, we have witnessed explosive growth in the understanding of normal and neoplastic lymphoid cells. B-cell, T-cell, and natural killer (NK)–cell neoplasms in many respects recapitulate normal stages of lymphoid cell differentiation and function, so that they can be to some extent classified according to the corresponding normal stage. Likewise, the molecular mechanisms involved the pathogenesis of lymphomas and lymphoid leukemias are often based on the physiology of the lymphoid cells, capitalizing on deregulated normal physiology by harnessing the promoters of genes essential for lymphocyte function. The clinical manifestations of lymphomas likewise reflect the normal function of lymphoid cells in vivo. The multiparameter approach to classification adopted by the World Health Organization (WHO) classification has been validated in international studies as being highly reproducible, and enhancing the interpretation of clinical and translational studies. In addition, accurate and precise classification of disease entities facilitates the discovery of the molecular basis of lymphoid neoplasms in the basic science laboratory.


Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1627-1637
Author(s):  
Peter Gaines ◽  
Laurie Tompkins ◽  
Craig T Woodard ◽  
John R Carlson

Abstract Remarkably little is known about the molecular mechanisms that drive sexual behavior. We have identified a new gene, quick-to-court (qtc), whose mutations cause males to show high levels of male-male courtship. qtc males also show a novel phenotype: when placed in the presence of a virgin female, they begin courtship abnormally quickly. qtc mutations are striking in their specificity, in that many aspects of male sexual behavior are normal. We have cloned the qtc gene and found that it encodes a predicted coiled-coil protein and is expressed in the olfactory organs, central nervous system, and male reproductive tract.


2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammed M. Almutairi ◽  
Farzane Sivandzade ◽  
Thamer H. Albekairi ◽  
Faleh Alqahtani ◽  
Luca Cucullo

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical manifestations of COVID-19 include dry cough, difficult breathing, fever, fatigue, and may lead to pneumonia and respiratory failure. There are significant gaps in the current understanding of whether SARS-CoV-2 attacks the CNS directly or through activation of the peripheral immune system and immune cell infiltration. Although the modality of neurological impairments associated with COVID-19 has not been thoroughly investigated, the latest studies have observed that SARS-CoV-2 induces neuroinflammation and may have severe long-term consequences. Here we review the literature on possible cellular and molecular mechanisms of SARS-CoV-2 induced-neuroinflammation. Activation of the innate immune system is associated with increased cytokine levels, chemokines, and free radicals in the SARS-CoV-2-induced pathogenic response at the blood-brain barrier (BBB). BBB disruption allows immune/inflammatory cell infiltration into the CNS activating immune resident cells (such as microglia and astrocytes). This review highlights the molecular and cellular mechanisms involved in COVID-19-induced neuroinflammation, which may lead to neuronal death. A better understanding of these mechanisms will help gain substantial knowledge about the potential role of SARS-CoV-2 in neurological changes and plan possible therapeutic intervention strategies.


2021 ◽  
Author(s):  
Nafisa Nuzhat ◽  
Kristof Van Schil ◽  
Sandra Liakopoulos ◽  
Miriam Bauwens ◽  
Alfredo Dueñas Rey ◽  
...  

Ciliopathies often comprise retinal degeneration since the photoreceptor outer segment is an adapted primary cilium. CEP162 is a distal end centriolar protein required for proper transition zone assembly during ciliogenesis and whose loss causes ciliopathy in zebrafish. CEP162 has so far not been implicated in human disease. Here, we identified a homozygous CEP162 frameshift variant, c.1935dupA (p.(E646R*5)), in retinitis pigmentosa patients from two unrelated Moroccan families, likely representing a founder allele. We found that even though mRNA levels were reduced, the truncated CEP162-E646R*5 protein was expressed and localized to the mitotic spindle during mitosis, but not at the basal body of the cilium. In CEP162 knockdown cells, expression of the truncated CEP162-E646R*5 protein is unable to restore ciliation indicating its loss of function at the cilium. In patient fibroblasts, cilia overcome the absence of CEP162 from the primary cilium by delaying ciliogenesis through the persistence of CP110 at the mother centriole. The patient fibroblasts are ultimately able to extend some abnormally long cilia that are missing key transition zone components. Defective transition zone formation likely disproportionately affects the long-living ciliary outer segment of photoreceptors resulting in retinal dystrophy. CEP162 is expressed in human retina, and we show that wild-type CEP162, but not truncated CEP162-E646R*5, specifically localizes to the distal end of centrioles of mouse photoreceptor cilia. Together, our genetic, cell-based, and in vivo modeling establish that CEP162 deficiency causes retinal ciliopathy in humans.


2021 ◽  
Author(s):  
C. R. Morton ◽  
N. J. Rzechorzek ◽  
J. D. Maman ◽  
M. Kuramochi ◽  
H. Sekiguchi ◽  
...  

AbstractThe DNA repair factor CtIP has a critical function in Double-Strand Break (DSB) repair by Homologous Recombination, promoting the assembly of the repair apparatus at DNA ends and participating in DNA-end resection. However, the molecular mechanisms of CtIP function in DSB repair remain unclear. Here we present an atomic model for the three-dimensional architecture of human CtIP, derived from a multi-disciplinary approach that includes X-ray crystallography, Small-angle X-ray Scattering (SAXS) and Diffracted X-ray Tracking (DXT). Our data show that CtIP adopts an extended dimer-of-dimers structure, in agreement with a role in bridging distant sites on chromosomal DNA during recombinational repair. The zinc-binding motif in CtIP’s N-terminus alters dynamically the coiled coil structure, with functional implications for the long-range interactions of CtIP with DNA. Our results provide a structural basis for the three-dimensional arrangement of chains in the CtIP tetramer, a key aspect of CtIP function in DNA DSB repair.


2012 ◽  
Vol 23 (11) ◽  
pp. 2076-2091 ◽  
Author(s):  
Qingwen Wan ◽  
Jing Liu ◽  
Zhen Zheng ◽  
Huabin Zhu ◽  
Xiaogang Chu ◽  
...  

Cell–cell contact formation following cadherin engagement requires actomyosin contraction along the periphery of cell–cell contact. The molecular mechanisms that regulate myosin activation during this process are not clear. In this paper, we show that two polarity proteins, partitioning defective 3 homologue (Par3) and mammalian homologues of Drosophila Lethal (2) Giant Larvae (Lgl1/2), antagonize each other in modulating myosin II activation during cell–cell contact formation in Madin-Darby canine kidney cells. While overexpression of Lgl1/2 or depletion of endogenous Par3 leads to enhanced myosin II activation, knockdown of Lgl1/2 does the opposite. Intriguingly, altering the counteraction between Par3 and Lgl1/2 induces cell–cell internalization during early cell–cell contact formation, which involves active invasion of the lateral cell–cell contact underneath the apical-junctional complexes and requires activation of the Rho–Rho-associated, coiled-coil containing protein kinase (ROCK)–myosin pathway. This is followed by predominantly nonapoptotic cell-in-cell death of the internalized cells and frequent aneuploidy of the host cells. Such effects are reminiscent of entosis, a recently described process observed when mammary gland epithelial cells were cultured in suspension. We propose that entosis could occur without matrix detachment and that overactivation of myosin or unbalanced myosin activation between contacting cells may be the driving force for entosis in epithelial cells.


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