Evidence map›Paper›PMID 41457018›Full record

ArticleThe FEBS journal2026

Detection of endogenous LINE-1 ORF2p and its potent reverse transcriptase activity in the MCF-7 breast cancer cell line.

Gopal Sarkar, Sujoy Kundu, Sulakshana P Mukherjee, John L Goodier, Prabhat K Mandal

Abstract read
In one paragraph

Article in The FEBS journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Gopal SarkarDepartment of Biosciences and Bioengineering, IIT Roorkee, India.
Sujoy KunduDepartment of Biosciences and Bioengineering, IIT Roorkee, India.
Sulakshana P MukherjeeDepartment of Chemical Sciences, Indian Institute of Science and Education Research (IISER) Berhampur, India.
John L GoodierJohns Hopkins School of Medicine, Baltimore, MD, USA.
Prabhat K MandalDepartment of Biosciences and Bioengineering, IIT Roorkee, India.ORCID https://orcid.org/0000-0002-9624-2543

Funding

Department of Biotechnology, Ministry of Science and Technology, India BT/PR41540/BRB/10/1960/2020Department of Science and Technology, Ministry of Science and Technology, India CRG/2021/002071
6 · The paper itself

Abstract

Long interspersed element-1 (LINE-1 or L1) is actively jumping in humans, notably in germ cells, neurons, and certain types of cancer. An active L1 is ~6.0 kb in length and encodes two proteins, designated ORF1p and ORF2p. L1 RNA binds with L1-encoded proteins and forms L1-ribonucleoprotein particles (L1-RNPs), the retrotransposition intermediate. Although cells that support L1 retrotransposition express both proteins, the detection of ORF2 protein (ORF2p) is extremely challenging due to its limited expression and unavailability of a suitable antibody. Here, we characterize an anti-ORF2p antibody and show the presence of endogenous L1-ORF2p in multiple cancer cell lines, among which the MCF-7 cell line showed notably high expression. Complexes purified by immunoprecipitation (IP) with anti-ORF2p or anti-ORF1p from MCF-7 or HEK293T cells contain ORF2p and ORF1p and show ORF2p-mediated reverse transcriptase (RT) activity on L1, Alu, and GAPDH RNA templates. The ORF2 IP complex was further purified by size exclusion chromatography (SEC), which showed three major peaks with molecular weights around 796, 427, and 239 kDa. All three peaks showed the presence of L1 proteins, RNA, and ORF2p-mediated RT activity. Although many proteins have been identified that interact with L1 proteins, it is unclear which of these belong to the core L1 RNP. Our novel anti-ORF2p will provide a valuable resource for future studies involving ORF2p IP followed by SEC to identify the protein components of core L1 RNPs. In summary, we report the detection of endogenous L1 ORF2 protein and partial purification of its complex by ORF2p antibody-coupled IP and SEC.

Indexed as

Breast NeoplasmsLong Interspersed Nucleotide ElementsRNA-Directed DNA PolymeraseEndonucleasesFemaleHEK293 CellsHumansImmunoprecipitationMCF-7 CellsEndonucleasesORF2 protein, humanRNA-Directed DNA Polymeraseanti‐ORF1panti‐ORF2pimmunoprecipitationL1 ribonucleoprotein particle (L1 RNP)LINE‐1ORF1ORF2retrotransposonreverse transcriptasesize exclusion chromatographyWestern blotting

Identifiers

PMID41457018
PMCPMC13370703

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.