In molecular biology the SPR domain is a protein domain found in the Sprouty (Spry) and Spred (Sprouty related EVH1 domain) proteins. These have been identified as inhibitors of the Ras/mitogen-activated protein kinase (MAPK) cascade, a pathway crucial for developmental processes initiated by activation of various receptor tyrosine kinases.[1][2] These proteins share a conserved, C-terminal cysteine-rich region, the SPR domain. This domain has been defined as a novel cytosol to membranetranslocation domain.[2][3][4][5] It has been found to be a PtdIns(4,5)P2-binding domain that targets the proteins to a cellular localization that maximizes their inhibitory potential.[2][6] It also mediates homodimer formation of these proteins.[3][6]
^Zhang S, Lin Y, Itäranta P, Yagi A, Vainio S (December 2001). "Expression of Sprouty genes 1, 2 and 4 during mouse organogenesis". Mechanisms of Development. 109 (2): 367–70. doi:10.1016/S0925-4773(01)00526-3. PMID11731251. S2CID17189370.
^Wakioka T, Sasaki A, Kato R, Shouda T, Matsumoto A, Miyoshi K, Tsuneoka M, Komiya S, Baron R, Yoshimura A (August 2001). "Spred is a Sprouty-related suppressor of Ras signalling". Nature. 412 (6847): 647–51. Bibcode:2001Natur.412..647W. doi:10.1038/35088082. PMID11493923. S2CID4345140.
^ abHanafusa H, Torii S, Yasunaga T, Nishida E (November 2002). "Sprouty1 and Sprouty2 provide a control mechanism for the Ras/MAPK signalling pathway". Nature Cell Biology. 4 (11): 850–8. doi:10.1038/ncb867. PMID12402043. S2CID31064800.