Schaapveld R Q, van den Maagdenberg A M, Schepens J T, Weghuis D O, Geurts van Kessel A, Wieringa B, Hendriks W J
Department of Cell Biology, University of Nijmegen, The Netherlands.
Genomics. 1995 May 1;27(1):124-30. doi: 10.1006/geno.1995.1014.
The human receptor-like protein tyrosine phosphatase leukocyte common antigen-related molecule (LAR; gene symbol PTPRF) closely resembles cell adhesion molecules, which suggests that it may be involved in the regulation of phosphotyrosine levels through cell-cell or cell-matrix interactions. To obtain a better understanding of LAR function, we have characterized the mouse Ptprf gene as a first step toward site-directed mutagenesis studies in vitro and in vivo. The cytoplasmic region of the mouse LAR (mLAR) protein is encoded by 11 exons that span only 4.5 kb of genomic DNA. Compared to the known exon-intron structures of other mammalian receptor-like protein tyrosine phosphatase genes, such as Ptpra (encoding LRP) and Ptprc (coding for Ly-5), the Ptprf gene part encoding the cytoplasmic region of mLAR contains not only smaller, but also fewer introns. Sequence analysis of both phosphatase domains of mLAR and its homologs MPTP delta and mRPTP sigma revealed a higher evolutionary conservation of the second, C-terminal domain in comparison to the first domain. Fluorescence in situ hybridization was used to map the Ptprf gene to region C6-D1 on mouse chromosome 4.
人类受体样蛋白酪氨酸磷酸酶白细胞共同抗原相关分子（LAR；基因符号PTPRF）与细胞粘附分子极为相似，这表明它可能通过细胞间或细胞与基质的相互作用参与磷酸酪氨酸水平的调节。为了更好地理解LAR的功能，我们已对小鼠Ptprf基因进行了特征描述，作为体外和体内定点诱变研究的第一步。小鼠LAR（mLAR）蛋白的胞质区域由11个外显子编码，这些外显子仅跨越4.5 kb的基因组DNA。与其他哺乳动物受体样蛋白酪氨酸磷酸酶基因（如编码LRP的Ptpra和编码Ly-5的Ptprc）已知的外显子-内含子结构相比，编码mLAR胞质区域的Ptprf基因部分不仅内含子更小，而且数量更少。对mLAR及其同系物MPTPδ和mRPTPσ的两个磷酸酶结构域进行序列分析发现，与第一个结构域相比，第二个C末端结构域具有更高的进化保守性。荧光原位杂交被用于将Ptprf基因定位到小鼠4号染色体上的C6-D1区域。
