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    Characterising parameters in Gcn1 relevant for Gcn2 activation : this dissertation is submitted for the degree of Doctor of Philosophy, Biochemistry, Massey University, Auckland, New Zealand. EMBARGOED to 29 March 2026.
    (Massey University, 2022) Gottfried, Susanne
    The protein kinase Gcn2 ("General control non-depressible" 2) is present in virtually all eukaryotic cells assessed thus far, from yeast to humans. Gcn2 supports the cells to cope with nutrient deficiency. Upon amino acid starvation, Gcn2 phosphorylates the alpha subunit of eukaryotic translation factor (eIF2α), which subsequently stimulates the translation of the transcription factor Gcn4. Gcn4 then induces the expression of stress-response genes involved in amino acid biosynthesis. At the same time, intracellular protein synthesis is downregulated. Activation of Gcn2 requires the binding of uncharged tRNA to the HisRS-like domain, which depends on the physical interaction between Gcn2 and Gcn1. Formation of the Gcn1-Gcn2 complex involves direct binding of the N-terminal RWD domain in Gcn2 to the RWD binding domain (RWDBD) in Gcn1. Malfunction of Gcn2 is implicated in various diseases such as cancer and Alzheimer's. By hyper-activating Gcn2, cancer cells take advantage of Gcn2 to satisfy their high nutrition demand. Healthy cells do not critically depend on Gcn2, making Gcn2 a promising target for potential drug development. Understanding Gcn2 function in detail may help identify suitable targets that prevent or treat such diseases. The aim of the study was to gain a deeper understanding of properties in Gcn1 determining binding to Gcn2 and test whether targeting the protein-protein interaction between Gcn1-Gcn2 could be a suitable approach to inhibit Gcn2.--Shortened abstract
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    Insect proteins : characterisation and development of meat analogues : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, Palmerston North, New Zealand. EMBARGOED until 1 March 2027.
    (Massey University, 2019) Gadodia, Varun
    Insect proteins are under constant exploration by researchers as a sustainable protein source to fulfil the rising needs of dietary proteins. Commercial insect powders are a rich source of protein having crude protein content up to 70 % on dry weight basis, which is equivalent to plant protein concentrates. In this study, commercially produced cricket powder was characterised for nutritional and functional attributes and further investigated for its ability to produce fibrous meat analogues when blended with plant proteins using a pilot-scale process. The specific objectives of current study were i) To determine nutritional value and functionality of commercial cricket powders; ii) To standardise a formulation using cricket powder and plant proteins blends for a pilot- scale process for producing meat analogues.--Shortened abstract
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    Identification of large ribosomal proteins required for the full activation of the protein kinase Gcn2 in Saccharomyces cerevisiae : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biological Sciences at Massey University, Albany, New Zealand. EMBARGOED indefinitely.
    (Massey University, 2019) Anderson, Reuben Andrew
    Protein synthesis is a fundamental biological process that all organisms require for maintaining life, growth and development. The maintenance of amino acid levels, the building blocks of proteins, is essential for maintaining protein synthesis under all biological conditions. Hence, amino acid shortage can be deleterious to the cell. Therefore, cells harbour mechanisms to cope and overcome amino acid starvation. When eukaryotes are subjected to amino acid starvation, the resulting accumulation of uncharged tRNAs activates the protein kinase Gcn2, leading to phosphorylation of eIF2α and activation of the amino acid starvation response. Uncharged tRNAs are the signal of starvation, directly detected by Gcn2. Gcn2 must bind to the effector protein Gcn1 and both must contact ribosomes for Gcn2 activation. The current working model for how the starvation signal is delivered to Gcn2 postulates that these uncharged tRNAs bind in the A-site of the ribosome in a codon specific manner, which are subsequently transferred to Gcn2. Gcn1 is directly involved in this process but its exact involvement is unknown. To test the working model, it is paramount to investigate where Gcn1 and Gcn2 bind on the ribosome. Ribosomes consist of a large and small subunit, each containing multiple ribosomal proteins placed in unique locations. Identification of ribosomal proteins contacting Gcn1 or Gcn2 will allow for deduction of where Gcn1 and Gcn2 bind on the ribosome. This study aimed to determine Gcn1 and Gcn2 contact points on the large ribosomal subunit, usinga genetic approach. The hypothesis was that if an interaction of Gcn1 or Gcn2 with a particular large ribosomal protein (Rpl) is important for Gcn2 activation, then its overexpression would impair Gcn2 function. Overexpression of several large ribosomal proteins impaired cell growth on a medium triggering amino acid starvation, suggesting Gcn2 activation was impaired. Groups of two or more of these Rpls were found in several regions which contain ribosomal proteins shown or suggested to interact with Gcn1 or Gcn2 previously. This included a region containing the P-stalk proteins (part of the large ribosomal complex) known to contact Gcn2. A region close to the small ribosomal protein Rps10, known to contact Gcn1, was also identified. Another region with Rpls which contacts a protein eEF3, which is suggested to share similar ribosomal contacts as Gcn1, was identified.