Question

One of the main energy molecules for tumor cells is glutamine (10 points)

 Choose one of the main glutamine transporters in mammalian cells, and using
PDB, provide an image of its molecular structure, and comment on its structure
shape. (Open your email in the tab next to the PDB tab in your browser while
you’re taking a screenshot of the protein image).
 According to the central dogma of biology, how many genes contribute to the
formation of this transporter, and provide their names?
 Provide a list of glutamine transporters that regulate glutamine influx to the cells
and out of the cells in a table format.
 From the biochemical perspective, what energy cycle does glutamine contribute
to? And what are the metabolites that get out of this cycle?
 Please provide a biological evaluation of why tumor cells' aggressiveness is
attributed to their dependency on glutamine consumption.

Answer 1

One of the main glutamine transporters in mammalian cells is SLC1A5. It is a sodium-coupled solute carrier that transports glutamine into cells.

SLC1A5 is a homodimeric protein that is composed of two identical subunits. Each subunit has 12 transmembrane helices. The two subunits are arranged in a head-to-tail fashion, with the N-termini of both subunits facing the extracellular space. The C-termini of both subunits face the cytoplasm.

The structure of SLC1A5 is important for its function. The transmembrane helices form a pore through the cell membrane that allows glutamine to pass into the cell. The sodium ions that are co-transported with glutamine are also transported through the pore. The binding sites for glutamine and sodium ions are located within the pore. According to the central dogma of biology, two genes contribute to the formation of SLC1A5: SLC1A5A and SLC1A5B.