期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2006
卷号：103
期号：31
页码：11595-11600
DOI：10.1073/pnas.0604766103
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In the Drosophila visual system, the color-sensing photoreceptors R7 and R8 project their axons to two distinct layers in the medulla. Loss of the receptor tyrosine phosphatase LAR from R7 photoreceptors causes their axons to terminate prematurely in the R8 layer. Here we identify a null mutation in the Liprin-{alpha} gene based on a similar R7 projection defect. Liprin-{alpha} physically interacts with the inactive D2 phosphatase domain of LAR, and this domain is also essential for R7 targeting. However, another LAR-dependent function, egg elongation, requires neither Liprin-{alpha} nor the LAR D2 domain. Although human and Caenorhabditis elegans Liprin-{alpha} proteins have been reported to control the localization of LAR, we find that LAR localizes to focal adhesions in Drosophila S2R+ cells and to photoreceptor growth cones in vivo independently of Liprin-{alpha}. In addition, Liprin-{alpha} overexpression or loss of function can affect R7 targeting in the complete absence of LAR. We conclude that Liprin-{alpha} does not simply act by regulating LAR localization but also has LAR-independent functions.
关键词：receptor tyrosine phosphatase ; visual system ; Drosophila
