Protein Domain : Regucalcin IPR008367

Type	Family
Description	Regucalcin, also known as senesence marker protein-30 (SMP30), wasdiscovered in 1978 as a Ca 2+binding protein that does not contain EF-hand motifs, suggesting a novel class of Ca2+binding protein. It is primarily localised to the liver and kidney cortex of animals. Expression of its mRNAin the liver and renal cortex of rats is stimulated by an increase in cellular Ca2+levels [ , ].Regucalin, as a regulatory protein of Ca2+, has a pivotal role in thecontrol of many cell functions. The protein has a reversible effect on Ca2+-induced activation and inhibition of many enzymes in both the liver and renal cortex cells []. It has also been shown to inhibit various proteinkinases (including Ca 2+/calmodulin-dependent protein kinase [ ], proteinkinase C [ ] and tyrosine kinase) and protein phosphatases, indicating aregulatory role in signal transduction within the cell. In addition, regucalcin regulates intracellular Ca2+homeostasis by enhancing Ca2+- pumping activity in the plasma membrane through activation of the pumpenzymes [ ]. Moreover, it can inhibit RNA synthesis in the nuclei of normaland regenerating rat livers in vitro [ ].Hydropathy profiles indicate hydrophobic domains in both N- and C-terminalregions of the regucalcin molecule; the protein also exhibits hydrophilic characteristics []. Human and rodent regucalcins share 89% sequenceidentity, the high degree of conservation between species suggesting that the complete structure is required for physiological function.
Short Name	Regucalcin