2005 Fiscal Year Final Research Report Summary
Functional analysis of Cas in adult tissues using conditional knockout mice
| Project/Area Number |
16590316
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Experimental pathology
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
HONDA Hiroaki Hiroshima University, Research Institute for Radiation Biology and Medicine, Professor, 原爆放射線医科学研究所, 教授 (40245064)
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| Project Period (FY) |
2004 – 2005
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| Keywords | p130 Cas (Cas) / actin / knockout mice / conditional knockout mice / コンディショナルノックアウトマウス |
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| Research Abstract |
p130Cas (Cas) is an adaptor protein identified as a highly tyrosine-phosphorylated molecule in fibroblasts transformed by v-Src or v-Crk oncoprotein. Cas has unique structural characteristics in that it as an SH (Src homology)-3 domain followed by multiple SH-2 biding motifs and a proline-rich region. To clarify its role in vivo, we generated mice deficient for Cas by gene targeting and demonstrated that Cas functions as an actin-binding molecule and is essential for embryogenesis and Src-mediated cellular transformation. But since Cas-deficient mice die in utero, the role(s) of Cas in adult tissues remains unclear. To address this issue, we tried to generate conditional knockout mice for Cas in which the Cas 2^<nd> exon that encodes the SH3 domain and a portion of SH2-binding motifs was encompassed by two loxP sites (Cas Δ exon2 cKO) and crossmated Cas Δ exon2 cKO with transgenic mice expressing Cre under the control of tissue-specific promoters. In these mice, we confirmed that Cas exon 2 was deleted in the targeted tissues, but we found that the message from exon 1 was fused to exon 3 in frame, which produced a truncated Cas protein. These mice were phenotypically indistinguishable from wild-type littermates (WT) and no abnormalities were found in pathological examinations, suggesting that the truncated Cas lacking exon2 compensates the function of Cas in adult tissues. So, we are now examining possible differences between Cas Δ exon2 cKO and WT when the mice are wounded or implanted with tumors. In addition, we are generating Cas full-length conditional knock tout mice (Cas FL cKO) in which Cas cDNA was inserted in exon 2 in frame and the coding region was encompassed by two loxP sites.
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