TY - JOUR
T1 - MEKK1 interacts with α-actinin and localizes to stress fibers and focal adhesion
AU - Christerson, Lori B.
AU - Vanderbilt, Colleen A.
AU - Cobb, Melanie H.
PY - 1999
Y1 - 1999
N2 - Mitogen-activated protein (MAP) kinases the effects of many extracellular stimuli on cells. The serine/threonine protein kinase MEKK1 is an upstream activator of the MAP kinases c-Jun N-terminal kinase/stress- activated protein kinase (JNK/SAPK), extracellular signal-regulated kinase (ERK), and p 38 as well as NF-κB. In a yeast two-hybrid interaction screen to identify proteins that bind to an N-terminal fragment of MEKK1 (amino acids 1-719), the actin-crosslinking protein α-actinin was identified as a MEKK1-binding protein. Over-expressed MEKK1 co-immunoprecipitated with α- actinin in cell lysates. Both endogenous and over-expressed MEKK1 colocalized with α-actinin along actin stress fibers and at focal adhesions. Residues 221-559 of MEKK1 bound to purified α-actinin in vitro, indicating that the interaction is direct, and this fragment localized to actin filaments in cells. MEKK1 kinase activity was not required for association with actin filaments, because a catalytically inactive mutant of MEKK1 (MEKK1 D1369A) localized to stress fibers. These results provide strong evidence for the interaction between MEKK1 and α-actinin. Thus, restriction of the kinase to the actin cytoskeleton may serve to regulate its specificity towards downstream targets.
AB - Mitogen-activated protein (MAP) kinases the effects of many extracellular stimuli on cells. The serine/threonine protein kinase MEKK1 is an upstream activator of the MAP kinases c-Jun N-terminal kinase/stress- activated protein kinase (JNK/SAPK), extracellular signal-regulated kinase (ERK), and p 38 as well as NF-κB. In a yeast two-hybrid interaction screen to identify proteins that bind to an N-terminal fragment of MEKK1 (amino acids 1-719), the actin-crosslinking protein α-actinin was identified as a MEKK1-binding protein. Over-expressed MEKK1 co-immunoprecipitated with α- actinin in cell lysates. Both endogenous and over-expressed MEKK1 colocalized with α-actinin along actin stress fibers and at focal adhesions. Residues 221-559 of MEKK1 bound to purified α-actinin in vitro, indicating that the interaction is direct, and this fragment localized to actin filaments in cells. MEKK1 kinase activity was not required for association with actin filaments, because a catalytically inactive mutant of MEKK1 (MEKK1 D1369A) localized to stress fibers. These results provide strong evidence for the interaction between MEKK1 and α-actinin. Thus, restriction of the kinase to the actin cytoskeleton may serve to regulate its specificity towards downstream targets.
KW - Cytoskeleton
KW - Focal adhesions
KW - Kinase
KW - MEKK1
KW - α-actinin
UR - http://www.scopus.com/inward/record.url?scp=0033046706&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033046706&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1097-0169(1999)43:3<186::AID-CM2>3.0.CO;2-1
DO - 10.1002/(SICI)1097-0169(1999)43:3<186::AID-CM2>3.0.CO;2-1
M3 - Article
C2 - 10401575
AN - SCOPUS:0033046706
SN - 0886-1544
VL - 43
SP - 186
EP - 198
JO - Cell Motility and the Cytoskeleton
JF - Cell Motility and the Cytoskeleton
IS - 3
ER -