Abstract：
Kings and queens of termites are endowed with an extraordinary longevity coupled with lifelong fecundity. We recently reported that termite kings and queens display a dramatically increased enzymatic activity and abundance of telomerase in their somatic organs when compared to short-lived workers and soldiers. We hypothesized that this telomerase activation may represent a noncanonical pro-longevity function, independent of its canonical role in telomere maintenance. Here, we explore this avenue and investigate whether the presumed noncanonical role of telomerase may be due to alternative splicing of the catalytic telomerase subunit TERT and whether the subcellular localization of TERT isoforms differs among organs and castes in the termite Prorhinotermes simplex. We empirically confirm the expression of four in silico predicted splice variants (psTERT1-A, psTERT1-B, psTERT2-A, psTERT2-B), defined by N-terminal splicing implicating differential localizations, and C-terminal splicing giving rise to full-length and truncated isoforms. We show that the transcript proportions of the psTERT are caste- and tissue-specific and that the extranuclear full-length isoform TERT1-A is relatively enriched in the soma of neotenic kings and queens compared to their gonads and to the soma of workers. We also show that extranuclear TERT protein quantities are significantly higher in the soma of kings and queens compared to workers, namely due to the cytosolic TERT. Independently, we confirm by microscopy the extranuclear TERT localization in somatic organs. We conclude that the presumed pleiotropic action of telomerase combining the canonical nuclear role in telomere maintenance with extranuclear functions is driven by complex TERT splicing.
摘要：
白蚁的国王和王后被赋予了非凡的长寿和终生的繁殖力。我们最近报道说，与短命的工人和士兵相比，白蚁王和王后的体细胞器官中的酶活性和端粒酶丰度显着增加。我们假设这种端粒酶激活可能代表了一种非规范的促长寿功能，独立于其在端粒维持中的典型作用。这里,我们探索了这一途径,并研究了端粒酶的推测的非规范作用是否可能是由于催化端粒酶亚基TERT的选择性剪接,以及TERT同工型的亚细胞定位是否在白蚁Prorhintermes单纯的器官和种姓中不同.我们根据经验证实了四种预测剪接变体(psTERT1-A，psTERT1-B,psTERT2-A,psTERT2-B)，由N端拼接定义，暗示差分本地化，和C末端剪接产生全长和截短的同种型。我们表明，psTERT的转录本比例是家族和组织特异性的，并且与性腺和工人的躯体相比，核外全长同工型TERT1-A在新科国王和王后的躯体中相对丰富。我们还表明，与工人相比，国王和王后的核外TERT蛋白数量明显更高，即由于细胞溶质TERT。独立地,我们通过显微镜确认了体细胞器官中的核外TERT定位。我们得出的结论是，端粒酶的假定多效作用将端粒维持中的规范核作用与核外功能相结合，是由复杂的TERT剪接驱动的。
