scholarly journals Structural basis of internal peptide recognition by PDZ domains using molecular dynamics simulations

2019 ◽  
Author(s):  
Neetu Sain ◽  
Debasisa Mohanty

AbstractPDZ domains are important peptide recognition modules which usually recognize short C-terminal stretches of their interaction partners, but certain PDZ domains can also recognize internal peptides in the interacting proteins. Due to the scarcity of data on internal peptide recognition and lack of understanding of the mechanistic details of internal peptide recognition, identification of PDZ domains capable of recognizing internal peptides has been a difficult task. Since Par-6 PDZ domain can recognize both C-terminal and internal peptides, we have carried out multiple explicit solvent MD simulations of 1 μs duration on free and peptide bound Par-6 PDZ to decipher mechanistic details of internal peptide recognition. These simulations have been analyzed to identify residues which play a crucial role in internal peptide recognition by PDZ domains. Based on the conservation profile of the identified residues, we have predicted 47 human PDZ domains to be capable of recognizing internal peptides in human. We have also investigated how binding of CDC42 to the CRIB domain adjacent to the Par6 PDZ allosterically modulate the peptide recognition by Par6 PDZ. Our MD simulations on CRIB-Par6_PDZ di-domain in isolation as well as in complex with CDC42, indicate that in absence of CDC42 the adjacent CRIB domain induces open loop conformation of PDZ facilitating internal peptide recognition. On the other hand, upon binding of CDC42 to the CRIB domain, Par6 PDZ adopts closed loop conformation required for recognition of C-terminus peptides. These results provide atomistic details of how binding of interaction partners onto adjacent domains can allosterically regulate substrate binding to PDZ domains. In summary, MD simulations provide novel insights into the modulation of substrate recognition preference of PDZ by specific peptides, adjacent domains and binding of interaction partners at allosteric sites.

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Doreen Korb ◽  
Priscilla Y. Tng ◽  
Vladimir M. Milenkovic ◽  
Nadine Reichhart ◽  
Olaf Strauss ◽  
...  

PDZ (PSD-95/Disc large/Zonula occludens-1) protein interaction domains bind to cytoplasmic protein C-termini of transmembrane proteins. In order to identify new interaction partners of the voltage-gated L-type Ca2+ channel 1.2 and the plasma membrane Ca2+ ATPase 4b (PMCA4b), we used PDZ domain arrays probing for 124 PDZ domains. We confirmed this by GST pull-downs and immunoprecipitations. In PDZ arrays, strongest interactions with 1.2 and PMCA4b were found for the PDZ domains of SAP-102, MAST-205, MAGI-1, MAGI-2, MAGI-3, and ZO-1. We observed binding of the 1.2 C-terminus to PDZ domains of NHERF1/2, Mint-2, and CASK. PMCA4b was observed to interact with Mint-2 and its known interactions with Chapsyn-110 and CASK were confirmed. Furthermore, we validated interaction of 1.2 and PMCA4b with NHERF1/2, CASK, MAST-205 and MAGI-3 via immunoprecipitation. We also verified the interaction of 1.2 and nNOS and hypothesized that nNOS overexpression might reduce Ca2+ influx through 1.2. To address this, we measured Ca2+ currents in HEK 293 cells co-expressing 1.2 and nNOS and observed reduced voltage-dependent 1.2 activation. Taken together, we conclude that 1.2 and PMCA4b bind promiscuously to various PDZ domains, and that our data provides the basis for further investigation of the physiological consequences of these interactions.


2020 ◽  
Vol 21 (4) ◽  
pp. 1401
Author(s):  
Stefano Borocci ◽  
Giulia Della Pelle ◽  
Francesca Ceccacci ◽  
Cristina Olivieri ◽  
Francesco Buonocore ◽  
...  

Antimicrobial peptides have been identified as one of the alternatives to the extensive use of common antibiotics as they show a broad spectrum of activity against human pathogens. Among these is Chionodracine (Cnd), a host-defense peptide isolated from the Antarctic icefish Chionodraco hamatus, which belongs to the family of Piscidins. Previously, we demonstrated that Cnd and its analogs display high antimicrobial activity against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species). Herein, we investigate the interactions with lipid membranes of Cnd and two analogs, Cnd-m3 and Cnd-m3a, showing enhanced potency. Using a combination of Circular Dichroism, fluorescence spectroscopy, and all-atom Molecular Dynamics (MD) simulations, we determined the structural basis for the different activity among these peptides. We show that all peptides are predominantly unstructured in water and fold, preferentially as α-helices, in the presence of lipid vesicles of various compositions. Through a series of MD simulations of 400 ns time scale, we show the effect of mutations on the structure and lipid interactions of Cnd and its analogs. By explaining the structural basis for the activity of these analogs, our findings provide structural templates to design minimalistic peptides for therapeutics.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miroslav Jurásek ◽  
Jitender Kumar ◽  
Petra Paclíková ◽  
Alka Kumari ◽  
Konstantinos Tripsianes ◽  
...  

AbstractThe PDZ domain of Dishevelled 3 protein belongs to a highly abundant protein recognition motif which typically binds short C-terminal peptides. The affinity of the PDZ towards the peptides could be fine-tuned by a variety of post-translation modifications including phosphorylation. However, how phosphorylations affect the PDZ structure and its interactions with ligands remains elusive. Combining molecular dynamics simulations, NMR titration, and biological experiments, we explored the role of previously reported phosphorylation sites and their mimetics in the Dishevelled PDZ domain. Our observations suggest three major roles for phosphorylations: (1) acting as an on/off PDZ binding switch, (2) allosterically affecting the binding groove, and (3) influencing the secondary binding site. Our simulations indicated that mimetics had similar but weaker effects, and the effects of distinct sites were non-additive. This study provides insight into the Dishevelled regulation by PDZ phosphorylation. Furthermore, the observed effects could be used to elucidate the regulation mechanisms in other PDZ domains.


2019 ◽  
Vol 25 (7) ◽  
pp. 783-816 ◽  
Author(s):  
Nizar A. Al-Shar'i ◽  
Qosay A. Al-Balas

: Adenosine receptors (ARs) are transmembrane proteins that belong to the G protein-coupled receptors (GPCRs) superfamily and mediate the biological functions of adenosine. To date, four AR subtypes are known, namely A1, A2A, A2B and A3 that exhibit different signaling pathways, tissue localization, and mechanisms of activation. Moreover, the widespread ARs and their implication in numerous physiological and pathophysiological conditions had made them pivotal therapeutic targets for developing clinically effective agents. : The crystallographic success in identifying the 3D crystal structures of A2A and A1 ARs has dramatically enriched our understanding of their structural and functional properties such as ligand binding and signal transduction. This, in turn, has provided a structural basis for a larger contribution of computational methods, particularly molecular dynamics (MD) simulations, toward further investigation of their molecular properties and designing bioactive ligands with therapeutic potential. MD simulation has been proved to be an invaluable tool in investigating ARs and providing answers to some critical questions. For example, MD has been applied in studying ARs in terms of ligand-receptor interactions, molecular recognition, allosteric modulations, dimerization, and mechanisms of activation, collectively aiding in the design of subtype selective ligands. : In this review, we focused on the advances and different applications of MD simulations utilized to study the structural and functional aspects of ARs that can foster the structure-based design of drug candidates. In addition, relevant literature was briefly discussed which establishes a starting point for future advances in the field of drug discovery to this pivotal group of drug targets.


2007 ◽  
Vol 282 (49) ◽  
pp. 35988-35999 ◽  
Author(s):  
Jiawen Wu ◽  
Yinshan Yang ◽  
Jiahai Zhang ◽  
Peng Ji ◽  
Wenjing Du ◽  
...  

Zonula occludens proteins (ZOs), including ZO1/2/3, are tight junction-associated proteins. Each of them contains three PDZ domains. It has been demonstrated that ZO1 can form either homodimers or heterodimers with ZO2 or ZO3 through the second PDZ domain. However, the underlying structural basis is not well understood. In this study, the solution structure of the second PDZ domain of ZO2 (ZO2-PDZ2) was determined using NMR spectroscopy. The results revealed a novel dimerization mode for PDZ domains via three-dimensional domain swapping, which can be generalized to homodimers of ZO1-PDZ2 or ZO3-PDZ2 and heterodimers of ZO1-PDZ2/ZO2-PDZ2 or ZO1-PDZ2/ZO3-PDZ2 due to high conservation between PDZ2 domains in ZO proteins. Furthermore, GST pulldown experiments and immunoprecipitation studies demonstrated that interactions between ZO1-PDZ2 and ZO2-PDZ2 and their self-associations indeed exist both in vitro and in vivo. Chemical cross-linking and dynamic laser light scattering experiments revealed that both ZO1-PDZ2 and ZO2-PDZ2 can form oligomers in solution. This PDZ domain-mediated oligomerization of ZOs may provide a structural basis for the polymerization of claudins, namely the formation of tight junctions.


2020 ◽  
Author(s):  
Amy O. Stevens ◽  
Yi He

ABSTRACTThe PDZ domain is a highly abundant protein-protein interaction domain that exists in many signaling proteins, such as PICK1. Despite the highly conserved structure of the PDZ family, the PDZ family has an extremely low sequence identity, making each PDZ domain unique. PICK1 is the only protein in the human genome that is comprised of a PDZ domain and a BAR domain. PICK1 regulates surface membrane proteins and has been identified as an integral player in drug addiction. Like many PDZ-containing proteins, PICK1 is positively regulated by its PDZ domain and has thus drawn attention to be a potential drug target to curb the effects of substance abuse. The goal of this study is to use all-atom molecular dynamics simulations and the electrostatic analysis program, DelPhi, to better understand the unique interactions and dynamic changes in the PICK1 PDZ domain upon complex formation. Our results demonstrated that the PICK1 PDZ domain shares similar canonical PDZ-ligand hydrogen bonding networks and fluctuations of the carboxylate-binding loop to other PDZ domains. Furthermore, our results are unique to the PICK1 PDZ domain as we reveal that the binding of ligand opens up the binding pocket and, at the same time, reduces the fluctuations of both the central part of the binding pocket and the short loop region between the αA-helix and βC-strand. More importantly, the binding of ligand resulted in charge redistribution at the binding pocket region as well as the N- and C-termini of the PDZ domain that are not a part of the binding pocket. These results suggest that the electrostatic allostery resulted from ligand binding could be the key factor leading to the changes in dynamics which may be associated with the activation of PICK1. Based on these results, an effective drug to target PDZ domain must not only stably bind to the PICK1 PDZ domain but also prevent the electrostatic allostery of the PDZ domain.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4540
Author(s):  
Vertika Gautam ◽  
Piyarat Nimmanpipug ◽  
Sharifuddin Md Zain ◽  
Noorsaadah Abd Rahman ◽  
Vannajan Sanghiran Lee

Extracellular signal-regulated kinases 1 and 2 (ERK1/2) play key roles in promoting cell survival and proliferation through the phosphorylation of various substrates. Remarkable antitumour activity is found in many inhibitors that act upstream of the ERK pathway. However, drug-resistant tumour cells invariably emerge after their use due to the reactivation of ERK1/2 signalling. ERK1/2 inhibitors have shown clinical efficacy as a therapeutic strategy for the treatment of tumours with mitogen-activated protein kinase (MAPK) upstream target mutations. These inhibitors may be used as a possible strategy to overcome acquired resistance to MAPK inhibitors. Here, we report a class of repeat proteins—designed ankyrin repeat protein (DARPin) macromolecules targeting ERK2 as inhibitors. The structural basis of ERK2–DARPin interactions based on molecular dynamics (MD) simulations was studied. The information was then used to predict stabilizing mutations employing a web-based algorithm, MAESTRO. To evaluate whether these design strategies were successfully deployed, we performed all-atom, explicit-solvent molecular dynamics (MD) simulations. Two mutations, Ala → Asp and Ser → Leu, were found to perform better than the original sequence (DARPin E40) based on the associated energy and key residues involved in protein-protein interaction. MD simulations and analysis of the data obtained on these mutations supported our predictions.


2020 ◽  
Author(s):  
Jing Yuan How ◽  
Rebecca K. Stephens ◽  
Krystle Y.B. Lim ◽  
Patrick O. Humbert ◽  
Marc Kvansakul

AbstractScribble is a critical cell polarity regulator that has been shown to work as either an oncogene or tumor suppressor in a context dependent manner, and also impacts cell migration, tissue architecture and immunity. Mutations in Scribble lead to neural tube defects in mice and humans, which has been attributed to a loss of interaction with the planar cell polarity regulator Vangl2. We show that the Scribble PDZ domains 1, 2 and 3 are able to interact with the C-terminal PDZ binding motif of Vangl2 and have now determined crystal structures of these Scribble PDZ domains bound to the Vangl2 peptide. Mapping of mammalian neural tube defect mutations reveal that mutations located distal to the canonical PDZ domain ligand binding groove can not only ablate binding to Vangl2 but also disrupt binding to multiple other signaling regulators. Our findings suggest that PDZ-associated neural tube defect mutations in Scribble may not simply act in a Vangl2 dependent manner but as broad-spectrum loss of function mutants by disrupting the global Scribble-mediated interaction network.


2021 ◽  
Author(s):  
Michael D Healy ◽  
Joanna Sacharz ◽  
Kerrie E McNally ◽  
Calum McConville ◽  
Ryan J Hall ◽  
...  

The sorting nexin SNX17 controls endosome-to-cell surface recycling of diverse transmembrane cargo proteins including integrins, the amyloid precursor protein and lipoprotein receptors. This requires association with the multi-subunit Commander trafficking complex, which depends on the C-terminus of SNX17 through unknown mechanisms. Using affinity enrichment proteomics, we find that a C-terminal peptide of SNX17 is not only sufficient for Commander interaction but also associates with members of the actin-associated PDZ and LIM domain (PDLIM) family. We show that SNX17 contains a type III PSD95/Dlg/Zo1 (PDZ) binding motif (PDZbm) that binds specifically to the PDZ domains of PDLIM family proteins but not to other PDZ domains tested. The structure of the PDLIM7 PDZ domain bound to the SNX17 C-terminus was determined by NMR spectroscopy and reveals an unconventional perpendicular peptide interaction. Mutagenesis confirms the interaction is mediated by specific electrostatic contacts and a uniquely conserved proline-containing loop sequence in the PDLIM protein family. Our results define the mechanism of SNX17-PDLIM interaction and suggest that the PDLIM proteins may play a role in regulating the activity of SNX17 in conjunction with Commander and actin-rich endosomal trafficking domains.


2021 ◽  
Vol 22 (11) ◽  
pp. 5961
Author(s):  
Jelena Vucinic ◽  
Gleb Novikov ◽  
Cédric Y. Montanier ◽  
Claire Dumon ◽  
Thomas Schiex ◽  
...  

With the growing need for renewable sources of energy, the interest for enzymes capable of biomass degradation has been increasing. In this paper, we consider two different xylanases from the GH-11 family: the particularly active GH-11 xylanase from Neocallimastix patriciarum, NpXyn11A, and the hyper-thermostable mutant of the environmentally isolated GH-11 xylanase, EvXyn11TS. Our aim is to identify the molecular determinants underlying the enhanced capacities of these two enzymes to ultimately graft the abilities of one on the other. Molecular dynamics simulations of the respective free-enzymes and enzyme–xylohexaose complexes were carried out at temperatures of 300, 340, and 500 K. An in-depth analysis of these MD simulations showed how differences in dynamics influence the activity and stability of these two enzymes and allowed us to study and understand in greater depth the molecular and structural basis of these two systems. In light of the results presented in this paper, the thumb region and the larger substrate binding cleft of NpXyn11A seem to play a major role on the activity of this enzyme. Its lower thermal stability may instead be caused by the higher flexibility of certain regions located further from the active site. Regions such as the N-ter, the loops located in the fingers region, the palm loop, and the helix loop seem to be less stable than in the hyper-thermostable EvXyn11TS. By identifying molecular regions that are critical for the stability of these enzymes, this study allowed us to identify promising targets for engineering GH-11 xylanases. Eventually, we identify NpXyn11A as the ideal host for grafting the thermostabilizing traits of EvXyn11TS.


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