Paxillin Isoforms in Mouse
LACK OF THE γ ISOFORM AND DEVELOPMENTALLY SPECIFIC β ISOFORM EXPRESSION*
- From the ‡Department of Molecular Biology, Osaka Bioscience Institute, Suita, Osaka 565-0874, **Precursory Research for Embryonic Science and Technology, Japan Science and Technology Corporation, Kyoto 619-02, §Institute for Virus Research, Kyoto University, Kyoto 606, ¶Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160, and‖Cancer Institute, Tokyo 170, Japan
Abstract
Paxillin, a focal adhesion protein, exists as multiple isoforms in humans (α, β, and γ). To understand more about the physiological role of each isoform, we have employed the mouse system. We found that although the α and β isoforms are present in the mouse, the γ isoform is not. The α isoform protein was detected clearly in most adult tissues, whereas the β isoform protein was almost undetectable except in spleen, testis, thymus, and lung. On the other hand, mRNAs of both isoforms were detectable in all tissues we examined. High levels of the β isoform protein was detected in peritoneal exudate macrophage cells in adult mouse as well as in cultured fibroblasts, together with the α isoform. The α isoform was expressed at a constant level throughout the embryonic stages we examined, whereas the β isoform protein was detected at the mid-stages of development and increased to levels almost equal to those of the α isoform during the late stages of embryogenesis. Therefore, unlike the α isoform, expression of the β isoform protein is restricted in adult tissues. Moreover, we showed that α and β isoforms were colocalized within the same focal adhesion plaques, and cytoplasmic pools of both isoforms exist in the perinuclear area, colocalized with the Golgi apparatus.
Footnotes
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↵* This work was supported by Japan Corporation of Science and Technology, and Grants-in-aid from the Ministry of Education, Science, Sports and Culture of Japan, 09253225 and 09281218, and a grant from Mitsubishi Foundation.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) AB014482.
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↵‡ To whom correspondence should be addressed. Tel.: 81-6-872-4814; Fax: 81-6-871-6686; E-mail: sabe{at}obi.or.jp.
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↵2 Y. Mazaki and H. Sabe, unpublished results.
- Abbreviations:
- PCR
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polymerase chain reaction
- RT-PCR
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reverse transcriptase-PCR
- BSA
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bovine serum albumin
- dpc
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days post coitus
- GFP
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green fluorescent protein
- PBS
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phosphate-buffered saline.
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- Received April 22, 1998.
- Revision received June 2, 1998.
- The American Society for Biochemistry and Molecular Biology, Inc.
