Effect of
            l
            ‐theanine on growth performance, intestinal development and health, and peptide and amino acid transporters expression of broilers

Tumorigenesis is driven by metabolic reprogramming. Oncogenic mutations and epigenetic alterations that cause metabolic rewiring may also upregulate the reactive oxygen species (ROS). Precise regulation of the intracellular ROS levels is critical for tumor cell growth and survival. High ROS production leads to the damage of vital macromolecules, such as DNA, proteins, and lipids, causing genomic instability and further tumor evolution. One of the hallmarks of cancer metabolism is deregulated amino acid uptake. In fast-growing tumors, amino acids are not only the source of energy and building intermediates but also critical regulators of redox homeostasis. Amino acid uptake regulates the intracellular glutathione (GSH) levels, endoplasmic reticulum stress, unfolded protein response signaling, mTOR-mediated antioxidant defense, and epigenetic adaptations of tumor cells to oxidative stress. This review summarizes the role of amino acid transporters as the defender of tumor antioxidant system and genome integrity and discusses them as promising therapeutic targets and tumor imaging tools.

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Pichia pastoris and the Recombinant Human Heterodimeric Amino Acid Transporter 4F2hc-LAT1: From Clone Selection to Pure Protein

Methods and Protocols ◽

10.3390/mps4030051 ◽

2021 ◽

Vol 4 (3) ◽

pp. 51

Author(s):

Satish Kantipudi ◽

Daniel Harder ◽

Sara Bonetti ◽

Dimitrios Fotiadis ◽

Jean-Marc Jeckelmann

Keyword(s):

Amino Acid ◽

Pichia Pastoris ◽

Protein Complexes ◽

Amino Acid Transporter ◽

Amino Acid Transporters ◽

Expression Host ◽

Amino Acids And Derivatives ◽

Heterodimeric Complex ◽

Acid Transporter ◽

And Function

Heterodimeric amino acid transporters (HATs) are protein complexes composed of two subunits, a heavy and a light subunit belonging to the solute carrier (SLC) families SLC3 and SLC7. HATs transport amino acids and derivatives thereof across the plasma membrane. The human HAT 4F2hc-LAT1 is composed of the type-II membrane N-glycoprotein 4F2hc (SLC3A2) and the L-type amino acid transporter LAT1 (SLC7A5). 4F2hc-LAT1 is medically relevant, and its dysfunction and overexpression are associated with autism and tumor progression. Here, we provide a general applicable protocol on how to screen for the best membrane transport protein-expressing clone in terms of protein amount and function using Pichia pastoris as expression host. Furthermore, we describe an overexpression and purification procedure for the production of the HAT 4F2hc-LAT1. The isolated heterodimeric complex is pure, correctly assembled, stable, binds the substrate L-leucine, and is thus properly folded. Therefore, this Pichia pastoris-derived recombinant human 4F2hc-LAT1 sample can be used for downstream biochemical and biophysical characterizations.

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Characterization of the third member of the MCAT family of cationic amino acid transporters. Identification of a domain that determines the transport properties of the MCAT proteins.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)36854-1 ◽

1993 ◽

Vol 268 (28) ◽

pp. 20796-20800

Author(s):

E.I. Closs ◽

C.R. Lyons ◽

C Kelly ◽

J.M. Cunningham

Keyword(s):

Amino Acid ◽

Transport Properties ◽

Amino Acid Transporters ◽

Cationic Amino Acid ◽

The Third

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LAT1 and ASCT2 Related microRNAs as Potential New Therapeutic Agents against Colorectal Cancer Progression

Biomedicines ◽

10.3390/biomedicines9020195 ◽

2021 ◽

Vol 9 (2) ◽

pp. 195

Author(s):

Francisca Dias ◽

Cristina Almeida ◽

Ana Luísa Teixeira ◽

Mariana Morais ◽

Rui Medeiros

Keyword(s):

Colorectal Cancer ◽

Amino Acid ◽

Cancer Progression ◽

Cell Metabolism ◽

Tumor Development ◽

Amino Acid Transporters ◽

Epigenetic Alterations ◽

Therapeutic Approaches ◽

Colorectal Cancer Progression ◽

Made In

The development and progression of colorectal cancer (CRC) have been associated with genetic and epigenetic alterations and more recently with changes in cell metabolism. Amino acid transporters are key players in tumor development, and it is described that tumor cells upregulate some AA transporters in order to support the increased amino acid (AA) intake to sustain the tumor additional needs for tumor growth and proliferation through the activation of several signaling pathways. LAT1 and ASCT2 are two AA transporters involved in the regulation of the mTOR pathway that has been reported as upregulated in CRC. Some attempts have been made in order to develop therapeutic approaches to target these AA transporters, however none have reached the clinical setting so far. MiRNA-based therapies have been gaining increasing attention from pharmaceutical companies and now several miRNA-based drugs are currently in clinical trials with promising results. In this review we combine a bioinformatic approach with a literature review in order to identify a miRNA profile with the potential to target both LAT1 and ASCT2 with potential to be used as a therapeutic approach against CRC.

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