Quantitative Assay of Cyclin-Dependent Kinase Activity As a Sensitive Marker of Cell Proliferation in Marine Teleost Larvae.
: An evolutionarily conserved family of cyclin-dependent kinases (Cdks) regulates cell cycle progression in eukaryotes. Mitosis-promoting factor (MPF) is a transiently activated Cdk required for mitosis. We propose use of partially purified MPF kinase activity as a sensitive marker of cell proliferation in marine teleost larvae and describe a quantitative spin-filter assay of suc1-precipitated MPF activity. MPF extracted from embryos and larvae of red drum, Sciaenops ocellatus, phosphorylated histone H1 protein and a Cdk-specific peptide substrate. Kinetic analyses demonstrated that apparent Km values of red drum MPF for adenosine triphosphate and the peptide substrate were 98.3 and 18.2 µM, respectively. A simple growth experiment showed that MPF activity was significantly greater in rapidly growing red drum larvae than in intermittently fed cohorts growing more slowly.
Westerman
ME
Department of Wildlife and Fisheries, 210 Nagle Hall, Texas A&M University, College Station, TX 77843, U.S.A.
Holt
GJ
DiMichele
L