Báo cáo khoa học: Death-associated protein kinase (DAPK) and signal transduction pptx

MINIREVIEW SERIES
Death-associated protein kinase (DAPK) and signal
transduction
Ted R. Hupp
CRUK p53 Signal Transduction Laboratories, Institute of Genetics and Molecular Medicine, University of Edinburgh, UK
Death-associated protein kinase-1 (DAPK) is the
prototypic member of a family of death-related kinases
that was originally identified as a factor that regulates
apoptosis in response to the death-inducing cytokine
signal interferon-c. DAPK has since been shown to play
a specialized role as a kinase that can regulate diverse
biological signals, including membrane blebbing,
autophagy, growth factor-induced survival, tumour
necrosis factor-mediated cell death, cancer development
and ischaemic-induced neuronal cell death.
Relatively little is known about how DAPK orches-
trates these diverse cellular events. There is a great
deal of knowledge on the genetic pathways that are
integrated into highly conserved eukaryotic signalling
kinases, such as ataxia telangiectasia mutated (ATM),
CDC2 and MAPK. This is mainly due to the fact that
these enzymes occur in genetically tractable organisms,
such as yeast, which makes pathway mapping relatively
rapid. However, many disease-causing genes in humans
are not present in yeast and have only evolved in
metazoans; DAPK is a case in point and this precludes
rapid genetic screens for epistatic pathway mapping.
This minireview series highlights some recent
advances in DAPK signal transduction biology. The
first minireview by Lin et al. highlights the use of
combinatorial peptide linear domain screens to identify

novel DAPK protein–protein interactions involved in
membrane blebbing and mammalian target of rapamy-
cin-containing complex signalling. The intriguing and
relatively ill-defined role of DAPK in membrane
blebbing is put into context in the second minireview
by Bovellan et al., which highlights fundamental func-
tions of membrane blebbing, not only in cell death,
but also in cytokinesis and autophagy. These latter
activities have critical implications for the role of
DAPK in growth control, especially as DAPK can
regulate the extent of membrane blebbing via interac-
tions with microtubule-associated protein 1B. This pro-
tein in turn interacts with the autophagy protein
family member ATG8, thus forming a novel link
between autophagy and membrane blebbing pathways.
The third minireview by Kang and Avery discusses
the use of the first genetic model (Caenorhabditis ele-
gans) for DAPK, which is driving fundamental insight
into the role of DAPK gene dosage in regulating the
extent of autophagic signalling. Autophagy is an evo-
lutionarily conserved lysosomal system used to degrade
abnormal or long-lived proteins and can be induced by
physiological stresses, including amino acid starvation
and pathogen infection. The genetic role of DAPK in
autophagy cannot be solved using yeast genetics and
the continued use of the C. elegans model will proba-
bly provide unique genetic insights into the role of
DAPK and its death domain in autophagy. The final
minireview in the series by Michie et al. reviews the
difficult task of acquiring clinically relevant knowledge

on any gene in medicine and in particular the role
DAPK gene is proving to have in cancer development.
The combined insights acquired using genetics, clin-
ical screens and signal transduction biology indicates
that the specific activity of DAPK is a pivotal feature
in explaining its diverse functions. How many
dynamic protein–protein interactions will integrate
with and regulate the DAPK signal? A recent study
attempting to define the ‘interactome’ of the DNA-
damage activatable kinase ATM indicated that over
700 substrates exist for this enzyme. This was far
more substrates than expected. Whether DAPK occu-
pies as complex a ‘hub’ as ATM will require further
cross-disciplinary research in this field to shed addi-
tional light on the role of the DAPK pathway in
biology and medicine.
Ted Hupp is Professor of Experimental Cancer Biochemistry at the Institute of Genetics and Molecular Medicine at the
University of Edinburgh. He received his PhD in Biochemistry in the laboratory of Jon Kaguni at Michigan State
University, MI, USA, studying the initiation of chromosomal DNA replication in Escherichia coli and worked as a post-
doctoral researcher with David Lane at the University of Dundee, UK, on the p53 tumour suppressor. The research in the
Hupp laboratory aims to define the role of phosphorylation in the control of the p53 tumour suppressor pathway and to
uncover the role of novel pro-oncogenic pathways, like anterior gradient-2, that inhibit the p53 pathway in human cancer.
doi:10.1111/j.1742-4658.2009.07410.x
FEBS Journal 277 (2010) 47 ª 2009 The Author Journal compilation ª 2009 FEBS 47