|Protein Name||Sodium-dependent phosphate transport protein 2B|
|Milk Fraction||Whey, MFGM, Exosome|
|Ref Sequence Id||NP_777086.1|
|Amino Acid Lenth||693|
|Protein Existence Status||Reviewed: Experimental evidence at protein level|
|Presence in other biological fluids/tissue/cells||renal epithelial cells, small intestine|
|Protein Function||renal Pi reabsorption; involved in Pi homeostasis; type 2b Na-dependent phosphate co-transporter (NaPi-2b) is the main mediator of intestinal active Pi absorption|
|Biochemical Properties||Na+ interacts in a cooperative way with the transporter with a stoichiometry of 3Na+ to 1Pi; Protons decreased the affinity of the transporter for Na+, resulting in the characteristic pH-dependency of Na+/Pi reabsorption; as found in bovine renal epithelial cell lines, presence of at least eight regions of hydrophobicity;|
|Significance in milk||nutrient transport systems for milk precursors and constituents|
|PTMs||Glycosylated:possible sites for N-glycosylation and phosphorylation by protein kinase C as found in bovine renal epithelial cells;|
|Bibliography||1. Busch, A. et al. (1994) ‘Electrophysiological analysis of Na+/Pi cotransport mediated by a transporter cloned from rat kidney and expressed in Xenopus oocytes.’, Proceedings of the National Academy of Sciences, 91(17), pp. 8205–8208. doi: 10.1073/pnas.91.17.8205. |
2. Hayes, G. et al. (1994) ‘Role of N-linked glycosylation in rat renal Na/Pi-cotransport.’, The Journal of biological chemistry, 269(39), pp. 24143–9. Available at: http://www.ncbi.nlm.nih.gov/pubmed/7929070 (Accessed: 4 October 2019).
3. Helps, C., Murer, H. and McGivan, J. (1995) ‘Cloning, Sequence Analysis and Expression of the cDNA Encoding a Sodium-Dependent Phosphate Transporter from the Bovine Renal Epithelial Cell Line NBL-1’, European Journal of Biochemistry, 228(3), pp. 927–930. doi: 10.1111/j.1432-1033.1995.tb20341.x.
4. Giral, H. et al. (2012) ‘NHE3 Regulatory Factor 1 (NHERF1) Modulates Intestinal Sodium-dependent Phosphate Transporter (NaPi-2b) Expression in Apical Microvilli’, Journal of Biological Chemistry, 287(42), pp. 35047–35056. doi: 10.1074/jbc.M112.392415.