Fluorescent Sensors of Protein Kinases: From Basics to Biomedical Applications - Progress in Molecular Biology and Translational Science - page 218

HCS high content screening
HTS high-throughput screening
KAR kinase activity reporter
NBD nitrobenzofuran
NES nuclear export sequence
NIRF near-infrared fluorescence
NLS nuclear localization sequence
PAABD phosphoamino acid-binding domain
PBD Polo Box Domain
PKA cAMP-dependent protein kinase A
PKB protein kinase B also known as Akt
PKC protein kinase C
PKD protein kinase D
PTB phosphotyrosine-binding domain
PTK protein tyrosine kinase
RDF recognition-domain-focused
RFP red fluorescent protein
RGD Cyclic Arginine-Glycine-Aspartate
SAPK stress-activated protein kinases
SH2 domain Src-homology 2 domain
SH3 domain Src-homology 3 domain
Sox sulfonamide-oxine
YFP yellow fluorescent protein

1. INTRODUCTION
1.1. Protein kinases

Structure, function, and mechanism

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of action
The first report of a phosphorylated proteinwas the identification of phosphor-
ylated vitellin (phosvitin) in 1906, followed by the detection of
phosphorylated casein in 1933. 1,2 Yet the enzymatic process of protein
phosphorylation itself was described only in 1954, with the identification of
an enzyme from rat liver mitochondria, namely, glycogen phosphorylase,
that could catalyze the transfer of phosphate from adenosine triphosphate
(ATP) to protein substrates, together with a complete characterization of the
conditions underlying this process, and reference made to emphasize the
high turnover rate of phosphorus and the reactivity of phosphoproteins in
tumors. 3 Today, we know that protein phosphorylation is the consequence
of a fine balance between the activities of protein kinases that add phosphate
groups and protein phosphatases that remove phosphate groups from protein
substrates, and that these activities are responsible for phosphorylation of up
to 30% of all cellular proteins. 4-7