Major urinary protein function

Held W., Gallagher J.F., Hohman C.M., Kuhn N.J., et al. (1987). Identification and characterization of functional genes encoding the mouse major urinary proteins. Mol Cell Biol 10, 3705-3712. 

Armstrong, S. D., Robertson, D. H. L., Cheetham, S. A., Hurst, J. L. and Beynon, R. J. (2005) Structural and functional differences in isoforms of mouse major urinary proteins a male-specific protein that preferentially binds a male pheromone. Biochem. J. 391, 343-350. 

The Biological Function of Cauxin, a Major Urinary Protein of the Domestic Cat (Felis catus)... 

Beynon RJ, Hurst JL, Gaskell SJ, Hubbard SJ, Humphries RE, Malone N, Marie AD, Martinsen L, Nevison CM, Payne CE, Robertson DHL, Veggerby C (2001) Mice MUPs and myths structure-function relationships of the major urinary proteins. In March-lewska-Koj A, Lepri JJ, Muller-Schwarze D (eds) Chemical signals in vertebrates IX. Cluver/Plenum, New York, p 149... 

Rat a2-gIobulin (A2U) and the homologous mouse protein (major urinary protein, MUP) are the principal proteins secreted in the urine of male rodents. Because male urine affects the behavior and sexual response of females, it has been suggested that these proteins function as pheromone-binding proteins. The crystal structures of both proteins have been determined (Bocskei et al., 1992). As expected (Cowan et al, 1990), both structures have the RBP fold. The Ca coordinates of the /3 barrel agree with an RMS difference of approximately 1.2 A. Both contain a ligand in the center of the barrel, where extensive interactions are made with the hydrophobic residues lining the barrel. For the MUP... 

A second highly polymorphic system that contributes to the urinary scents of mice is the major urinary protein (MUP) complex (Beynon and Hurst, 2003). These small lipocalin proteins have a central cavity that binds and releases semiochemicals. Unlike MHC, the only known function of these proteins is in chemical signalling and they are... 

Beynon, R.J., Robertson, D., Hubbard, S.J., Gaskell, S.J., and Hurst, J. 199. The major urinary proteins of the mouse Molecular heterogeneity and function. This volume. 

Not only is the structure of the sex pheromone identical in both moths and Asian elephants and its function similar, but the study of protein carriers promises to be equally fascinating. The delineation of postulated protein carriers for this acetate has the potential to provide similar evolutionary information about lipocalin-like urinary proteins and pheromone binding proteins. Insect pheromone binding proteins that bind Z7—12 Ac have a different amino acid composition and two-dimensional structure than vertebrate odorant binding proteins so far described, including major urinary proteins (Robertson, Cox, Gaskell, Evershed Beynon, 1996 Steinbrecht, 1996 Pelosi, 1994). 

The major urinary proteins (MUPs) are secreted abundantly into mouse urine as a normal condition. MUPs are thought to be involved in olfactory communication as their distinctive barrel shape allows them to bind two semiochemical molecules. Production of MUPs results from simultaneous expression of a number of closely related MUP genes the mature proteins therefore have heterogeneous amino acid sequences. Whilst this heterogeneity has been characterised in inbred mice, little is known about the heterogeneity of MUPs in wild mice. No function has ever been ascribed to MUP heterogeneity. 

Biotinidase is also the major plasma binding protein for biotin. The pH optimum of the enzyme is 4.5 to 5.5, and its is in the micromolar range, compared with the nanomolar concentrations of biocytin, so it will have little enzymic activity in plasma. Rather, it functions as a transport protein for biotin, preventing its urinary excretion children with biotinidase deficiency (Section 11.2.3.1) excrete large amounts of both biocytin and free biotin. Biotin is covalently bound to biotinidase in plasma, as a thioester to a cysteine residue in the active site of the enzyme (see Figure 11.1). This thioester is formed only from biocytin, not free biotin, and is presumably the (normally transient)... 

If one had to state an overall role of copper in the body, one might say oxygen metabolism. One major factor shared by both zinc and copper is that both metal ions occur bound to metallothionein. The function of metallothionein is not firmly established. Copper is bound to another protein, ceruloplasmin, which occurs in the cell and plasma. The function of this protein is not clear either. Zinc absorption, as iron absorption, is impaired by high levels of phytic acid. Copper absorption is not inhibited by phytic acid. The major route of excretion of both metal ions is fecal, rather than urinary. 

The pH of urine is dependent on the cationic and anionic composition, with the cationic products of normal metabolism buffered by the renal handling of bicarbonate and dietary protein content affecting urinary pH. In catabolic states associated with severe toxicity, the urinary pH may be lowered. Thus, changes of pH may reflect major metabolic perturbations, changes in tubular function, or the presence of xeno-biotics and/or their metabolites in urine. 

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