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Concentration of ERK in oocytes

Value	1.2 µM
Organism	African clawed frog Xenopus laevis
Reference	Huang CY and Ferrell JE Jr., Ultrasensitivity in the mitogen-activated protein kinase cascade. Proc Natl Acad Sci U S A. 1996 Sep 17 93(19):10078-83. p. 10081 table 1PubMed ID8816754
Method	Concentrated Xenopus oocyte extracts were prepared as described (refs 20-22 in article). The washed, defolliculated oocytes were centrifuged at low speeds to remove excess buffer, and crushed by centrifugation. The cytoplasm was collected, clarified by centrifugation, and stored at -80°C. The steady-state activity of Mek-1 was assessed by a linked immune complex kinase assay, and the activity of p42 MAPK by a myelin basic protein kinase assay (ref 23 in article).
Comments	The conc. of Mek-1 (a MAPKK) and p42 MAPK was estimated to be 1.2 µM.
Entered by	Cellina Cohen-Saidon
ID	100882