tailieunhanh - Báo cáo khoa học: Degradation of nuclear DNA by DNase II-like acid DNase in cortical fiber cells of mouse eye lens

The eye lens is composed of fiber cells that differentiate from epithelial cells on its anterior surface. In concert with this differentiation, a set of proteins essential for lens function is synthesized, and the cellular organelles are degraded. DNase II-like acid DNase, also called DNase IIb, is specifically expressed in the lens, and degrades the DNA in the lens fiber cells. | ỊFEBS Journal Degradation of nuclear DNA by DNase II-like acid DNase in cortical fiber cells of mouse eye lens Masaki Nakahara1 Akiomi Nagasaka2 Masato Koike3 Kaori Uchida1 Kohki Kawane1 2 Yasuo Uchiyama3 and Shigekazu Nagata1 2 4 1 Department of Genetics Osaka University MedicalSchool Japan 2 Laboratory of Genetics Integrated Biology Laboratories Graduate Schoolof Frontier Biosciences Osaka University Japan 3 Department of Cell Biology and Neuroscience Osaka University Medical School Japan 4 Solution Oriented Research for Science and Technology Japan Science and Technology Corporation Osaka Japan Keywords acid DNase differentiation eye lens gene array lysosome Correspondence S. Nagata Department of Medical Chemistry Graduate Schoolof Medicine Kyoto University Yoshida Sakyo-ku Kyoto 606-8501 Japan Fax 81 75 753 9446 Tel 81 75 753 9441 E-mail snagata@ Website http pub genetic English o20Site HP 20top 89p 8c oea Home 20top Received 28 February 2007 revised 9 April 2007 accepted 17 April 2007 doi The eye lens is composed of fiber cells that differentiate from epithelial cells on its anterior surface. In concert with this differentiation a set of proteins essential for lens function is synthesized and the cellular organelles are degraded. DNase II-like acid DNase also called DNase IIP is specifically expressed in the lens and degrades the DNA in the lens fiber cells. Here we report that DNase II-like acid DNase is synthesized as a precursor with a signal sequence and is localized to lysosomes. DNase II-like acid DNase mRNA was found in cortical fiber cells but not epithelial cells indicating that its expression is induced during the differentiation of epithelial cells into fiber cells. Immunohistochemical and immunocytochemical analyses indicated that DNase II-like acid DNase was colocalized with Lamp-1 in the lysosomes of fiber cells in a relatively narrow region bordering the .