Reynolds D S, Gurley D S, Austen K F, Serafin W E
Department of Medicine, Harvard Medical School, Boston, Massachusetts.
J Biol Chem. 1991 Feb 25;266(6):3847-53.
The cDNA and gene for mouse mast cell protease-6 (MMCP-6) have been sequenced and show MMCP-6 to be translated as a prepro-enzyme with a 21-amino acid hydrophobic leader peptide, a 10-amino acid activation peptide, and a 245-amino acid mature enzyme. The mature form of the enzyme has 73% amino acid sequence identity with human and dog mast cell tryptases. The MMCP-6 gene includes 6 exons, with a total span of 1.8 kilobases. A 208-base pair intron was defined which separates the 5'-untranslated sequence of MMCP-6 from the translation initiation codon, thereby presenting a gene organization which distinguishes tryptic serine proteases from chymotryptic serine proteases of the mast cell secretory granule. By RNA blot analysis with a gene-specific probe, MMCP-6 has a unique subclass distribution in being transcribed in mouse connective tissue mast cells but undetectable in mucosal mast cells. MMCP-6 is the first serine protease of any class to be shown to be significantly transcribed in progenitor, bone marrow-derived mast cells, which can reconstitute both mucosal mast cell and connective tissue mast cell populations in mast cell-deficient mice.
已对小鼠肥大细胞蛋白酶-6（MMCP-6）的互补DNA（cDNA）和基因进行了测序，结果显示MMCP-6被翻译为一种前体酶原，它含有一个21个氨基酸的疏水前导肽、一个10个氨基酸的激活肽和一个245个氨基酸的成熟酶。该酶的成熟形式与人和犬肥大细胞类胰蛋白酶具有73%的氨基酸序列同一性。MMCP-6基因包含6个外显子，总跨度为1.8千碱基。确定了一个208碱基对的内含子，它将MMCP-6的5'非翻译序列与翻译起始密码子分隔开，从而呈现出一种基因结构，该结构将肥大细胞分泌颗粒中的胰蛋白酶样丝氨酸蛋白酶与糜蛋白酶样丝氨酸蛋白酶区分开来。通过用基因特异性探针进行RNA印迹分析，MMCP-6具有独特的亚类分布，它在小鼠结缔组织肥大细胞中被转录，但在粘膜肥大细胞中无法检测到。MMCP-6是首个被证明在祖细胞、骨髓来源的肥大细胞中大量转录的任何类别的丝氨酸蛋白酶，这些肥大细胞可以在肥大细胞缺陷小鼠中重建粘膜肥大细胞和结缔组织肥大细胞群体。
