Ankycorbin: a novel actin cytoskeleton-associated protein.
BACKGROUND
Actin cytoskeleton structures are essential for a wide variety of cell functions, including cell shape change, cell motility, cell adhesion, cell polarity and cytokinesis. Many actin filament (F-actin)-binding proteins have been isolated and implicated in the maintenance and reorganization of actin cytoskeleton structures.


RESULTS
We purified here a novel protein with a molecular mass of about 125 kDa (p125) from rat liver. We cloned its cDNA from a mouse kidney cDNA library and determined its nucleotide and deduced amino acid sequences. p125 was a protein of 979 amino acids with a calculated Mr of 108 847. p125 contained six ankyrin repeats in the N-terminal region and a domain predicted to form a coiled-coil structure in the C-terminal region. We named p125 ankycorbin (ankyrin repeat- and coiled-coil structure-containing protein). Northern blot analysis indicated that ankycorbin was ubiquitously expressed in all the tissues examined. Immunofluorescence and immunoelectron microscope analyses revealed that ankycorbin was associated with the cortical actin cytoskeleton structures in terminal web and cell-cell adhesion sites and stress fibres. However, ankycorbin did not directly bind to F-actin as estimated by the F-actin co-sedimentation assay.


CONCLUSIONS
These results indicate that ankycorbin is indirectly associated with the actin cytoskeleton structures, presumably through an unidentified factor and suggest that it is involved in their maintenance and/or reorganization.
Peng
Y F
YF
Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine/Faculty of Medicine, Suita 565-0871, Japan.
Mandai
K
K
Sakisaka
T
T
Okabe
N
N
Yamamoto
Y
Y
Yokoyama
S
S
Mizoguchi
A
A
Shiozaki
H
H
Monden
M
M
Takai
Y
Y
D016475:3T3 Cells; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017487:Ankyrins / Q000378:metabolism; D019556:COS Cells; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D011817:Rabbits; D051381:Rats; D014157:Transcription Factors; D014162:Transfection
D000199:Actins; D017487:Ankyrins; D003598:Cytoskeletal Proteins; C428450:RAI14 protein, human; C486074:Rai14 protein, mouse; C486073:Rai14 protein, rat; D014157:Transcription Factors