Watson K L, Chou M M, Blenis J, Gelbart W M, Erikson R L
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Proc Natl Acad Sci U S A. 1996 Nov 26;93(24):13694-8. doi: 10.1073/pnas.93.24.13694.
cDNAs encoding the Drosophila 70-kDa S6 kinase (S6K) were isolated by low-stringency hybridization with mammalian p70S6k probes. Conceptual translation of S6k cDNA sequences yields a product containing all of the canonical features typical of serine/threonine kinases and has 78% amino acid identity in the catalytic domain with the human p70S6k homologue. The S6k gene, located at polytene chromosome site 65D, gives rise to two predominant transcripts of 3.0 and 5.0 kb and at least two smaller transcripts (< 3.0 kb) that are found in whole-animal RNAs at all stages of development. Blood cells derived from the hematopoietic organs of ribosomal protein S6 (RpS6air8) mutant animals express higher levels of the smaller S6k transcripts, suggesting tissue- or genotype-specific differences in the regulation of the S6k gene. Drosophila S6K expressed in COS or NIH 3T3 cells phosphorylates mammalian RPS6 in a mitogen-dependent wortmannin- and rapamycin-sensitive manner, suggesting that its regulation is similiar to mammalian p70S6k.
通过与哺乳动物p70S6k探针进行低严谨度杂交，分离出了编码果蝇70 kDa S6激酶（S6K）的cDNA。对S6k cDNA序列进行概念性翻译，产生的产物包含丝氨酸/苏氨酸激酶所有典型的规范特征，并且在催化结构域中与人p70S6k同源物具有78%的氨基酸同一性。位于多线染色体位点65D的S6k基因产生3.0 kb和5.0 kb两种主要转录本，以及至少两种较小的转录本（<3.0 kb），这些转录本在发育的所有阶段的全动物RNA中都能找到。来自核糖体蛋白S6（RpS6air8）突变动物造血器官的血细胞表达较高水平的较小S6k转录本，这表明S6k基因的调控存在组织或基因型特异性差异。在COS或NIH 3T3细胞中表达的果蝇S6K以依赖有丝分裂原的、渥曼青霉素和雷帕霉素敏感的方式磷酸化哺乳动物RPS6，这表明其调控与哺乳动物p70S6k相似。
