Deregulated expression of KRAP, a novel gene encoding actin-interacting protein, in human colon cancer cells.
We have identified a novel gene, designated KRAP (Ki- ras-induced actin-interacting protein), encoding a protein of 1,259 amino acids with coiled-coil regions and transmembrane regions, from the cDNA library of human colon cancer HCT116 cells, as one of the genes upregulated by activated Ki- ras. While KRAP was rarely expressed in normal colon epithelium, deregulated constitutive KRAP expression was observed in some other colon cancer cells. In normal tissues, KRAP was strongly expressed in pancreas and testis. Anti-KRAP polyclonal antibodies detected endogenous KRAP as the molecular size of Mr 180,000, and immunofluorescence microscopy and cytochalasin E treatment revealed that KRAP was clearly associated with the actin filaments. Furthermore, KRAP was localized as a membrane-bound form with extracellular regions. These results together suggested KRAP might be involved in the regulation of filamentous actin and signals from the outside of the cells.
Inokuchi
Junichi
J
Department of Pathology, Research Institute, International Medical Center of Japan, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan.|Department of Urology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Komiya
Misako
M
Department of Pathology, Research Institute, International Medical Center of Japan, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan.
Baba
Iwai
I
Department of Pathology, Research Institute, International Medical Center of Japan, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan.
Naito
Seiji
S
Department of Urology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Sasazuki
Takehiko
T
Research Institute, International Medical Center of Japan, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan.
Shirasawa
Senji
S
Department of Pathology, Research Institute, International Medical Center of Japan, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan. sshirasawa@ri.imcj.go.jp.
D000595:Amino Acid Sequence; D019921:Biotinylation; D015152:Blotting, Northern; D003572:Cytochalasins; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D015723:Gene Library; D011905:Genes, ras / Q000235:genetics*; D045325:HCT116 Cells; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010179:Pancreas / Q000378:metabolism; D011233:Precipitin Tests; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013737:Testis / Q000378:metabolism; D014162:Transfection
D003572:Cytochalasins; C482653:ITPRID2 protein, human; D008565:Membrane Proteins; D008840:Microfilament Proteins; C007215:cytochalasin E