Seegobin Mark, Kisiala Anna, Noble Adam, Kaplan David, Brunetti Craig, Emery R J Neil
Department of Biology, Trent University, Peterborough, Ontario, Canada.
Noblegen, Peterborough, Ontario, Canada.
FASEB J. 2018 Jun 12:fj201800347. doi: 10.1096/fj.201800347.
Cytokinins (CKs) are a group of phytohormones essential to plant growth and development. The presence of these N-modified adenine derivatives has also been documented in other groups of organisms, including bacteria, fungi, and insects. Thus far, however, only a single CK, N-(Δ-isopentenyl) adenine-9-riboside (iPR), has been identified in mammals. In plants, the nucleotide form of isopentenyladenine [iPR (either mono-, di-, or tri-) phosphate (iPRP)] is the first form of CK synthesized, and it is further modified to produce other CK types. To determine if a similar biosynthesis pathway exists in mammals, we tested for the presence of 27 CKs in a wide selection of canine organs using HPLC electrospray ionization-tandem mass spectrometry. Seven forms of CK were detected in the majority of the analyzed samples, including iPR, iPRP, cis-zeatin-9-riboside, cis-zeatin-9-riboside-5' (either mono-, di-, or triphosphate), 2-methylthio-N-isopentenyladenine, 2-methylthio-N-isopentenyladenosine, and 2-methylthio-zeatin. Total CK concentrations ranged from 1.96 pmol/g fresh weight (adrenal glands) to 1.40 × 10 pmol/g fresh weight (thyroid). The results of this study provide evidence that mammalian cells, like plant cells, can synthesize and process a diverse set of CKs including cis- and methylthiol-type CKs.-Seegobin, M., Kisiala, A., Noble, A., Kaplan, D., Brunetti, C., Emery, R. J. N. Canis familiaris tissues are characterized by different profiles of cytokinins typical of tRNA degradation pathway.
细胞分裂素（CKs）是一类对植物生长发育至关重要的植物激素。在包括细菌、真菌和昆虫在内的其他生物群体中也已证实存在这些N-修饰的腺嘌呤衍生物。然而，迄今为止，在哺乳动物中仅鉴定出一种细胞分裂素，即N-（Δ-异戊烯基）腺嘌呤-9-核糖苷（iPR）。在植物中，异戊烯基腺嘌呤的核苷酸形式[iPR（单、二或三）磷酸（iPRP）]是合成的第一种细胞分裂素形式，并且它会进一步修饰以产生其他类型的细胞分裂素。为了确定哺乳动物中是否存在类似的生物合成途径，我们使用高效液相色谱-电喷雾电离串联质谱法，在多种犬类器官中检测了27种细胞分裂素的存在情况。在大多数分析样本中检测到了七种形式的细胞分裂素，包括iPR、iPRP、顺式玉米素-9-核糖苷、顺式玉米素-9-核糖苷-5'（单、二或三磷酸）、2-甲硫基-N-异戊烯基腺嘌呤、2-甲硫基-N-异戊烯基腺苷和2-甲硫基玉米素。细胞分裂素的总浓度范围为1.96皮摩尔/克鲜重（肾上腺）至1.40×10皮摩尔/克鲜重（甲状腺）。这项研究的结果提供了证据，表明哺乳动物细胞与植物细胞一样，可以合成和加工多种细胞分裂素，包括顺式和甲硫醇型细胞分裂素。——西格宾，M.，基西亚拉，A.，诺布尔，A.，卡普兰，D.，布鲁内蒂，C.，埃默里，R.J.N. 家犬组织具有tRNA降解途径典型的不同细胞分裂素谱特征。
