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  1. Article: DeepSLICEM: Clustering CryoEM particles using deep image and similarity graph representations.

    Palukuri, Meghana V / Marcotte, Edward M

    bioRxiv : the preprint server for biology

    2024  

    Abstract: Finding the 3D structure of proteins and their complexes has several applications, such as developing vaccines that target viral proteins effectively. Methods such as cryogenic electron microscopy (cryo-EM) have improved in their ability to capture high- ... ...

    Abstract Finding the 3D structure of proteins and their complexes has several applications, such as developing vaccines that target viral proteins effectively. Methods such as cryogenic electron microscopy (cryo-EM) have improved in their ability to capture high-resolution images, and when applied to a purified sample containing copies of a macromolecule, they can be used to produce a high-quality snapshot of different 2D orientations of the macromolecule, which can be combined to reconstruct its 3D structure. Instead of purifying a sample so that it contains only one macromolecule, a process that can be difficult, time-consuming, and expensive, a cell sample containing multiple particles can be photographed directly and separated into its constituent particles using computational methods. Previous work, SLICEM, has separated 2D projection images of different particles into their respective groups using 2 methods, clustering a graph with edges weighted by pairwise similarities of common lines of the 2D projections. In this work, we develop DeepSLICEM, a pipeline that clusters rich representations of 2D projections, obtained by combining graphical features from a similarity graph based on common lines, with additional image features extracted from a convolutional neural network. DeepSLICEM explores 6 pretrained convolutional neural networks and one supervised Siamese CNN for image representation, 10 pretrained deep graph neural networks for similarity graph node representations, and 4 methods for clustering, along with 8 methods for directly clustering the similarity graph. On 6 synthetic and experimental datasets, the DeepSLICEM pipeline finds 92 method combinations achieving better clustering accuracy than previous methods from SLICEM. Thus, in this paper, we demonstrate that deep neural networks have great potential for accurately separating mixtures of 2D projections of different macromolecules computationally.
    Language English
    Publishing date 2024-02-08
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.02.04.578778
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Super.Complex: A supervised machine learning pipeline for molecular complex detection in protein-interaction networks.

    Palukuri, Meghana V / Marcotte, Edward M

    bioRxiv : the preprint server for biology

    2021  

    Abstract: Characterization of protein complexes, ...

    Abstract Characterization of protein complexes,
    Language English
    Publishing date 2021-10-11
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2021.06.22.449395
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Molecular complex detection in protein interaction networks through reinforcement learning.

    Palukuri, Meghana V / Patil, Ridhi S / Marcotte, Edward M

    BMC bioinformatics

    2023  Volume 24, Issue 1, Page(s) 306

    Abstract: Background: Proteins often assemble into higher-order complexes to perform their biological functions. Such protein-protein interactions (PPI) are often experimentally measured for pairs of proteins and summarized in a weighted PPI network, to which ... ...

    Abstract Background: Proteins often assemble into higher-order complexes to perform their biological functions. Such protein-protein interactions (PPI) are often experimentally measured for pairs of proteins and summarized in a weighted PPI network, to which community detection algorithms can be applied to define the various higher-order protein complexes. Current methods include unsupervised and supervised approaches, often assuming that protein complexes manifest only as dense subgraphs. Utilizing supervised approaches, the focus is not on how to find them in a network, but only on learning which subgraphs correspond to complexes, currently solved using heuristics. However, learning to walk trajectories on a network to identify protein complexes leads naturally to a reinforcement learning (RL) approach, a strategy not extensively explored for community detection. Here, we develop and evaluate a reinforcement learning pipeline for community detection on weighted protein-protein interaction networks to detect new protein complexes. The algorithm is trained to calculate the value of different subgraphs encountered while walking on the network to reconstruct known complexes. A distributed prediction algorithm then scales the RL pipeline to search for novel protein complexes on large PPI networks.
    Results: The reinforcement learning pipeline is applied to a human PPI network consisting of 8k proteins and 60k PPI, which results in 1,157 protein complexes. The method demonstrated competitive accuracy with improved speed compared to previous algorithms. We highlight protein complexes such as C4orf19, C18orf21, and KIAA1522 which are currently minimally characterized. Additionally, the results suggest TMC04 be a putative additional subunit of the KICSTOR complex and confirm the involvement of C15orf41 in a higher-order complex with HIRA, CDAN1, ASF1A, and by 3D structural modeling.
    Conclusions: Reinforcement learning offers several distinct advantages for community detection, including scalability and knowledge of the walk trajectories defining those communities. Applied to currently available human protein interaction networks, this method had comparable accuracy with other algorithms and notable savings in computational time, and in turn, led to clear predictions of protein function and interactions for several uncharacterized human proteins.
    MeSH term(s) Humans ; Protein Interaction Maps ; Algorithms ; Transcription Factors ; Protein Interaction Mapping/methods ; Computational Biology/methods ; Glycoproteins ; Nuclear Proteins ; Cell Cycle Proteins ; Molecular Chaperones
    Chemical Substances Transcription Factors ; CDAN1 protein, human ; Glycoproteins ; Nuclear Proteins ; ASF1A protein, human ; Cell Cycle Proteins ; Molecular Chaperones
    Language English
    Publishing date 2023-08-02
    Publishing country England
    Document type Journal Article
    ZDB-ID 2041484-5
    ISSN 1471-2105 ; 1471-2105
    ISSN (online) 1471-2105
    ISSN 1471-2105
    DOI 10.1186/s12859-023-05425-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Entrainment of superoxide rhythm by menadione in HCT116 colon cancer cells.

    Kizhuveetil, Uma / Palukuri, Meghana V / Sharma, Priyanshu / Karunagaran, Devarajan / Rengaswamy, Raghunathan / Suraishkumar, G K

    Scientific reports

    2019  Volume 9, Issue 1, Page(s) 3347

    Abstract: Reactive oxygen species (ROS) are primary effectors of cytotoxicity induced by many anti-cancer drugs. Rhythms in the pseudo-steady-state (PSS) levels of particular intracellular ROS in cancer cells and their relevance to drug effectiveness are unknown ... ...

    Abstract Reactive oxygen species (ROS) are primary effectors of cytotoxicity induced by many anti-cancer drugs. Rhythms in the pseudo-steady-state (PSS) levels of particular intracellular ROS in cancer cells and their relevance to drug effectiveness are unknown thus far. We report that the PSS levels of intracellular superoxide (SOX), an important ROS, exhibit an inherent rhythm in HCT116 colon cancer cells, which is entrained (reset) by the SOX inducer, menadione (MD). This reset was dependent on the expression of p53, and it doubled the sensitivity of the cells to MD. The period of oscillation was found to have a linear correlation with MD concentration, given by the equation, T, in h = 23.52 - 1.05 [MD concentration in µM]. Further, we developed a mathematical model to better understand the molecular mechanisms involved in rhythm reset. Biologically meaningful parameters were obtained through parameter estimation techniques; the model can predict experimental profiles of SOX, establish qualitative relations between interacting species in the system and serves as an important tool to understand the profiles of various species. The model was also able to successfully predict the rhythm reset in MD treated hepatoma cell line, HepG2.
    MeSH term(s) HCT116 Cells ; Humans ; Periodicity ; Superoxides/metabolism ; Vitamin K 3/metabolism
    Chemical Substances Superoxides (11062-77-4) ; Vitamin K 3 (723JX6CXY5)
    Language English
    Publishing date 2019-03-04
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-019-40017-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Entrainment of superoxide rhythm by menadione in HCT116 colon cancer cells

    Uma Kizhuveetil / Meghana V. Palukuri / Priyanshu Sharma / Devarajan Karunagaran / Raghunathan Rengaswamy / G. K. Suraishkumar

    Scientific Reports, Vol 9, Iss 1, Pp 1-

    2019  Volume 12

    Abstract: Abstract Reactive oxygen species (ROS) are primary effectors of cytotoxicity induced by many anti-cancer drugs. Rhythms in the pseudo-steady-state (PSS) levels of particular intracellular ROS in cancer cells and their relevance to drug effectiveness are ... ...

    Abstract Abstract Reactive oxygen species (ROS) are primary effectors of cytotoxicity induced by many anti-cancer drugs. Rhythms in the pseudo-steady-state (PSS) levels of particular intracellular ROS in cancer cells and their relevance to drug effectiveness are unknown thus far. We report that the PSS levels of intracellular superoxide (SOX), an important ROS, exhibit an inherent rhythm in HCT116 colon cancer cells, which is entrained (reset) by the SOX inducer, menadione (MD). This reset was dependent on the expression of p53, and it doubled the sensitivity of the cells to MD. The period of oscillation was found to have a linear correlation with MD concentration, given by the equation, T, in h = 23.52 − 1.05 [MD concentration in µM]. Further, we developed a mathematical model to better understand the molecular mechanisms involved in rhythm reset. Biologically meaningful parameters were obtained through parameter estimation techniques; the model can predict experimental profiles of SOX, establish qualitative relations between interacting species in the system and serves as an important tool to understand the profiles of various species. The model was also able to successfully predict the rhythm reset in MD treated hepatoma cell line, HepG2.
    Keywords Medicine ; R ; Science ; Q
    Subject code 612
    Language English
    Publishing date 2019-03-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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