- Peptide (C)SQKVQESERAFTYS, corresponding to amino acid residues 155-168 of mouse VNUT (Accession Q8VCL5). Intracellular, 2nd loop.
- Mouse and rat brain membranes, human SH-SY5Y neuroblastoma cell line lysate (1:200-1:2000).
- Western blot analysis of mouse (lanes 1 and 3) and rat (lanes 2 and 4) brain membranes:1,2. Anti-SLC17A9 Antibody (#ANT-085), (1:200).
3,4. Anti-SLC17A9 Antibody, preincubated with SLC17A9 Blocking Peptide (#BLP-NT085).
- Western blot analysis of human SH-SY5Y neuroblastoma cell line lysate:1. Anti-SLC17A9 Antibody (#ANT-085), (1:400).
2. Anti-SLC17A9 Antibody, preincubated with SLC17A9 Blocking Peptide (#BLP-NT085).
- Rat brain sections (1:2000).
The vesicular nucleotide transporter (VNUT), also known as SLC17A9, is a member of the solute carrier superfamily, which contains ~300 proteins. Members of the SLC17 family are expressed in intracellular membranes and insulated vesicles such as the lysosomes1.
SLC17A9 has 430 amino acids and predicted to have 12 transmembrane domains with both the carboxyl- and N-termini facing the same direction5. Although the human SLC17A9 ortholog displays sequence-specific modification of its N-terminus, SLC17A9 is highly conserved across species, which is believed to dictate its substrate preference5.
SLC17A9 is widely expressed in many tissues, especially in ATP containing vesicles4. In the brain, SLC17A9 is highly expressed in different regions such as the cortex, cerebellum, hippocampus, and olfactory bulbs, but also in astrocytes and microglia cells. SLC17A9 expression is also evident outside the central nervous system, such as in the gastrointestinal tract and the lungs4.
Unlike other SLC17 members, SLC17A9 is highly specific for phosphorylated nucleotides with particularly high affinity for ATP3. Silencing of SLC17A9 in PC12 cells revealed its fundamental role in ATP homeostasis as it dramatically reduced ATP concentrations in storage and secretory vesicles. In addition, SLC17A9 also plays a role in the immune system where it activates neutrophils by influencing ATP storage in secretory vesicles2.
Under specific circumstances, SLC17A9 is involved in different pathological conditions. For example, in the spinal cord, SLC17A9 expression is associated with a general incline to feel pain3. Moreover, SLC17A9 is also involved in the development of glaucoma in mice, possibly by regulating ATP secretion3.