Biology subjects

Leier, A.

Publications and source records attributed to Leier, A..

3 recordsLinked to original sources

bioRxiv2026

Cell line resources for the study of neurofibromin: functions, phenotypes, and drug discovery/development

Our labs have been studying neurofibromin function and phenotype for over a decade with the intent of generating targeted therapeutics for Neurofibromatosis type 1 (NF1). In the process, we have generated numerous human cell lines containing variants within the NF1 gene. Herein, we present data characterizing these cell lines and make them publicly available for use by researchers both within and outside the NF1 community. We describe lines that contain both well-characterized patient-specific variants either at their endogenous locus or as exogenous cDNAs, as well as variants of uncertain significance (VUS), engineered as heterozygous, homozygous, and compound heterozygous variants. Methods to generate each line and subsequent validation steps are detailed including targeted sequencing, Western blot analysis for neurofibromin expression and ERK activation. The utility of each line is dependent on the variant of interest, the parental cell line, and the mechanism of action relevant to possible therapeutic targeting.

genetics↗

bioRxiv2023

A role for JAK2 in mediating cell surface GHR-PRLR interaction

Growth hormone (GH) receptor (GHR) and (full-length) prolactin (PRL) receptor (PRLR) are transmembrane class I cytokine receptors that co-exist in various normal and cancerous cells. Both receptors respond to their associated ligands predominantly by activating the Janus Kinase 2 (JAK2)-signal transducer and activator of transcription (STAT) signaling pathways, and both are also known to initiate receptor-specific JAK2-independent signaling. Together with their cognate ligands, these receptors have been associated with pro-tumorigenic effects in various cancers, including breast cancer (BC). Human GH is known to bind GHR and PRLR, while PRL can only bind PRLR. A growing body of work suggests that GHR and PRLR can form heteromers in BC cells, modulating GH signal transduction. However, the dynamics of PRLR and GHR on the plasma membrane and how these could affect their respective signaling still need to be understood. To this end, we set out to unravel the spatiotemporal dynamics of GHR and PRLR on the surface of human T47D breast cancer cells and {gamma}2A-JAK2 cells. We applied direct stochastic optical reconstruction microscopy (dSTORM) and quantified the colocalization and availability of both receptors on the plasma membrane at the nanometer scale at different time points following treatment with GH and PRL. In cells co-expressing GHR and PRLR, we surprisingly observed that not only GH but also PRL treatment induces a significant loss of surface GHR. In cells lacking PRLR or expressing a mutant PRLR deficient in JAK2 binding, we observed that GH induces downregulation of cell surface membrane-bound GHR, but PRL no longer induces loss of surface GHR. Colocalizations of GHR and PRLR were confirmed by proximity ligation (PL) assay. Our results suggest that PRLR-GHR interaction, direct or indirect, is indispensable for PRL- but not GH- induced loss of surface GHR and for both GH-induced and PRL-induced increase of surface PRLR, with potential consequences for downstream signaling. Furthermore, our results suggest that JAK2 binding via the receptor intracellular domains Box1 element is crucial for the observed regulation of one class I cytokine receptors cell surface availability via ligand-induced activation of another class I cytokine receptor. Our findings shed new light on the reciprocal and collective role that PRLR and GHR play in regulating cell signaling.

biophysics↗

bioRxiv2019

PRISM: a comprehensive 3D structure database for post-translational modifications and mutations with functional impact

Post-translational modifications (PTMs) play very important roles in various cell signalling pathways and biological process. Due to PTMs extremely important roles, many major PTMs have been thoroughly studied, while the functional and mechanical characterization of major PTMs is well-documented in several databases. However, most currently available databases mainly focus on protein sequences, while the real 3D structures of PTMs have been largely ignored. Therefore, studies of PTMs 3D structural signatures have been severely limited by the deficiency of the data. Here, we develop PRISMOID, a novel publicly available and free 3D structure database for a wide range of PTMs. PRISMOID represents an up-to-date and interactive online knowledge base with specific focus on 3D structural contexts of PTMs sites and mutations that occur on PTMs and in the close proximity of PTM sites with functional impact. The first version of PRISMOID encompasses 17,145 non-redundant modification sites on 3,919 related protein 3D structure entries pertaining to 37 different types of PTMs. Our entry web page is organized in a comprehensive manner, including detailed PTM annotation on the 3D structure and biological information in terms of mutations affecting PTMs, secondary structure features and per-residue solvent accessibility features of PTM sites, domain context, predicted natively disordered regions and sequence alignments. In addition, high-definition JavaScript packages are employed to enhance information visualization in PRISMOID. PRISMOID equips a variety of interactive and customizable search options and data browsing functions; these capabilities allow users to access data via keyword, ID, and advanced options combination search in an efficient and user-friendly way. A download page is also provided to enable users to download the SQL file, computational structural features, and PTM sites data. We anticipate PRISMOID will swiftly become an invaluable online resource, assisting both biologists and bioinformaticians to conduct experiments and develop applications supporting discovery efforts in the sequence-structural-functional relationship of PTMs and providing important insight into mutations and PTM sites interaction mechanisms. The PRISMOID database is freely accessible at http://prismoid.erc.monash.edu/. The database and web interface are implemented in MySQL, JSP, JavaScript, and HTML with all major browsers supported.

bioinformatics↗