MICAL, a novel CasL interacting molecule, associates with vimentin.
CasL/HEF1 belongs to the p130(Cas) family. It is tyrosine-phosphorylated following beta(1) integrin and/or T cell receptor stimulation and is thus considered to be important for immunological reactions. CasL has several structural motifs such as an SH3 domain and a substrate domain and interacts with many molecules through these motifs. To obtain more insights on the CasL-mediated signal transduction, we sought proteins that interact with the CasL SH3 domain by far Western screening, and we identified a novel human molecule, MICAL (a Molecule Interacting with CasL). MICAL is a protein of 118 kDa and is expressed in the thymus, lung, spleen, kidney, testis, and hematopoietic cells. MICAL has a calponin homology domain, a LIM domain, a putative leucine zipper motif, and a proline-rich PPKPP sequence. MICAL associates with CasL through this PPKPP sequence. MICAL is a cytoplasmic protein and colocalizes with CasL at the perinuclear area. Through the COOH-terminal region, MICAL also associates with vimentin that is a major component of intermediate filaments. Immunostaining revealed that MICAL localizes along with vimentin intermediate filaments. These results suggest that MICAL may be a cytoskeletal regulator that connects CasL to intermediate filaments.
Suzuki
Takahiro
T
Department of Hematology and Oncology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Nakamoto
Tetsuya
T
Ogawa
Seishi
S
Seo
Sachiko
S
Matsumura
Tomoko
T
Tachibana
Kouichi
K
Morimoto
Chikao
C
Hirai
Hisamaru
H
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008840:Microfilament Proteins; D008856:Microscopy, Fluorescence; D006899:Mixed Function Oxygenases; D008969:Molecular Sequence Data; D010957:Plasmids; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D014746:Vimentin / Q000378:metabolism*; D000096985:Calponins
D048868:Adaptor Proteins, Signal Transducing; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008840:Microfilament Proteins; D006899:Mixed Function Oxygenases; D012333:RNA, Messenger; D014746:Vimentin; C455272:MICAL1 protein, human; D000096985:Calponins