What Is L1TD1? Gene and Protein Background

L1TD1 (LINE-1 type transposase domain-containing protein 1) is a gene and protein that emerged from the domestication of a LINE-1 retrotransposon-derived open reading frame during mammalian evolution. The human L1TD1 gene encodes an RNA-binding protein that retains structural homology to the ORF1p protein of LINE-1 retrotransposons, including an RNA recognition motif (RRM) domain, while having lost transposase catalytic activity.

L1TD1 is considered a hallmark marker of pluripotency. Its expression is highly restricted to undifferentiated human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs), and it is rapidly silenced upon the onset of differentiation. This tight expression pattern makes L1TD1 a valuable research tool for characterizing stem cell identity and studying the molecular networks that govern pluripotency.

At the molecular level, L1TD1 functions as an RNA-binding protein that associates with other key pluripotency regulators, including OCT4 (POU5F1), SOX2, and NANOG, as well as components of the RNA-processing machinery. It is believed to contribute to pluripotency maintenance by regulating the stability or translation of mRNAs encoding critical stem cell factors.

Biochemical Properties of Recombinant Human L1TD1 Protein

Recombinant Human L1TD1 Protein (SKU: rp372988) produced by Aladdin Scientific is designed to support a wide range of in vitro biochemical and cell biology experiments. As a recombinant protein, it is produced using established expression systems that allow for consistent batch-to-batch quality suited to demanding research applications.

Key biochemical characteristics of L1TD1 include its RNA-binding capability mediated through the RRM domain, its ability to form protein–protein interactions with pluripotency transcription factors, and its cytoplasmic localization in pluripotent cells. These properties collectively underpin its utility in assays designed to dissect RNA–protein interaction networks and stem cell regulatory circuits.

Note to researchers: Specific physicochemical parameters such as molecular weight, purity grade, formulation buffer, and storage conditions for SKU rp372988 should be confirmed in the current product datasheet available from Aladdin Scientific, as these specifications may be updated. Always refer to the official Certificate of Analysis (CoA) for lot-specific data.

Research Applications of L1TD1 Protein

Recombinant Human L1TD1 Protein is a versatile research reagent applicable across multiple experimental platforms:

• Pluripotency and Stem Cell Research: L1TD1 serves as a functional reagent and positive control marker to study the molecular mechanisms of pluripotency maintenance in hESCs and iPSCs. It can be used in gain-of-function and loss-of-function experimental frameworks to understand how RNA-binding proteins contribute to stem cell identity.
• RNA–Protein Interaction Studies: Given its RRM domain, recombinant L1TD1 protein is suitable for RNA pull-down assays, electrophoretic mobility shift assays (EMSA), and RNA immunoprecipitation (RIP) experiments designed to identify L1TD1-associated RNA targets.
• Protein–Protein Interaction Assays: L1TD1 can be used in co-immunoprecipitation (Co-IP) or surface plasmon resonance (SPR) studies to characterize its interaction with pluripotency factors (e.g., OCT4, NANOG) and ribonucleoprotein complex components.
• Antibody Validation: Recombinant L1TD1 protein serves as a reliable antigen standard for validating anti-L1TD1 antibodies used in Western blot, immunofluorescence, and ELISA applications.
• Structural Biology: High-purity recombinant L1TD1 may support crystallography or cryo-EM studies aimed at elucidating the three-dimensional structure of this RNA-binding protein and its complexes.

Handling, Storage, and Quality Considerations

To ensure optimal performance of Recombinant Human L1TD1 Protein in downstream applications, researchers should observe the following general best practices for handling recombinant proteins:

• Storage: Follow the storage conditions specified on the product datasheet and CoA. Recombinant proteins are generally stored at –20 °C or –80 °C depending on formulation; avoid repeated freeze–thaw cycles which can cause aggregation and loss of activity.
• Aliquoting: Upon first thaw, prepare single-use aliquots to minimize freeze–thaw degradation.
• Protein Concentration: Use validated protein quantification methods (e.g., BCA or Bradford assay) calibrated to the protein buffer to accurately determine working concentrations.
• Activity Verification: Where possible, confirm protein activity or integrity via SDS-PAGE, Western blot, or functional RNA-binding assay prior to critical experiments.
• Contamination Prevention: Handle under sterile conditions when preparing samples for cell-based assays to prevent microbial contamination.

Always consult the current Aladdin Scientific product datasheet (SKU: rp372988) for lot-specific storage conditions, recommended working concentrations, and quality control data.