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THE JOURNEY FROM DNA TO PROTEIN:
UNDERSTANDING THE ROLE OF YWHAG IN PROTEIN SYNTHESIS
Discover the journey of protein synthesis within our bodies, starting from the DNA blueprint up to the formation of complex protein structures. This guide is designed to help you understand the intricate process of how proteins are created and how genetic mutations, such as in the YWHAG gene, can affect this process and the overall health of the body.
THE PROCESS OF PROTEIN SYNTHESIS
#1. DNA:
THE GENETIC BLUEPRINT
• Location: DNA is stored in the nucleus of each cell and contains the instructions needed to make proteins.
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• Function: Segments of DNA called genes encode the specific instructions for synthesizing proteins.
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#2. TRANSCRIPTION:
FROM DNA TO mRNA
• Initiation: Transcription begins when the cell needs to produce a protein. Enzymes in the nucleus unwind the DNA, exposing the gene that codes for the protein.
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• mRNA Synthesis: RNA polymerase, an enzyme, then copies the gene’s code into messenger RNA (mRNA), a process akin to transcribing a note from a book.
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• Travel to Cytoplasm: The mRNA strand, carrying the genetic message, exits the nucleus and enters the cytoplasm.
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#3. TRANSLATION:
mRNA TO PROTEIN
• Ribosome Engagement: mRNA attaches to a ribosome, the cell’s protein factory.
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• Codon Recognition: Ribosomes read the mRNA in sets of three nucleotides, known as codons, each specifying an amino acid.
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• tRNA Matching: Transfer RNA (tRNA) molecules bring the correct amino acids to the ribosome, pairing them with the matching codons on the mRNA strand.
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• Polypeptide Formation: As each amino acid is added, it is linked to the growing chain, forming a polypeptide that will fold into a functional protein.
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CODONS:
THE BUILDING BLOCKS OF PROTEIN SYNTHESIS
• Definition: Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids or signal the start or end of protein synthesis.
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• Role in Translation: The sequence of codons determines the order of amino acids in the protein, influencing its final shape and function.
Image via Biologyonline.com
All the genetic information is encrypted in the DNA molecule. The genetic information is then transferred to mRNA as codons. The codons are eventually expressed as protein. Thus, the basic function of the codon is to encode the amino acid which eventually forms the proteins.
AMINO ACID PAIRING AND PROTEIN STRUCTURE
• Sequence Determination: The order of amino acids, dictated by the mRNA codons, determines the protein’s structure and function.
• Folding: After synthesis, the polypeptide chain folds into a three-dimensional structure, a process essential for the protein’s functionality.
Image via Biologyonline.com
Image via Biologyonline.com
Image via Biologyonline.com
UNDERSTANDING THE PROTEIN FOLDING PROCESS
Protein folding is like a high-stakes game of origami, where the prize is a tiny machine that does exactly what your body needs it to do. Here are the four main stages of this intricate process:
1. Primary Structure: This is the protein’s unique sequence of amino acids, like the specific order of folds and cuts in a piece of paper you would make before starting origami. Just as the pattern on the paper will determine the final origami shape, the sequence of amino acids determines the protein's final shape.
2. Secondary Structure: This stage involves creating patterns like alpha helices (spirals) or beta sheets (folds) from the sequence of amino acids. Think of it as the basic folds you first make in a piece of paper in origami, which starts to give it a new shape but isn't the final product yet.
3. Tertiary Structure: Now things get more complex. The simple folds start to tuck into each other and form a 3D structure. In our origami analogy, this is when your paper starts to look like a bird, a plane, or whatever you’re folding. For proteins, this is where they start to look like the machines or tools they are meant to be.
4. Quaternary Structure: Some proteins need to team up with other proteins to do their job, just like some origami shapes might be combined to make something more complex, for example a paper crane with flapping wings. This stage is where those proteins come together and assemble into a final, multi-unit structure.
At the end of this process, the protein is ready to perform its specific function in the cell, just like your completed origami figure is ready to be displayed!
Image Credit: Image modified from OpenStax Biology's modification of work by the National Human Genome Research Institute.
PROTEIN DIMERIZATION AND CELLULAR FUNCTIONS
• Formation of Dimers: Some proteins, including the one encoded by YWHAG, must form dimers (pairs of proteins) to become active.
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• Binding and Activity: These dimers can bind to other molecules or compounds, facilitating vital biological processes such as cell signaling and metabolism.
ROLE OF YWHAG
• Cell Signaling: The YWHAG gene encodes a protein involved in cellular signaling pathways, crucial for normal cell function and communication.
MUTATION CONSEQUENCES
• Dimerization Disruption: Mutations in YWHAG can affect the protein’s ability to form dimers, leading to impaired binding and signaling functions.