Molecular Entomology Laboratory, RIKEN Advanced Science Institute Wako, Japan.
Front Endocrinol (Lausanne). 2012 Jan 24;3:6. doi: 10.3389/fendo.2012.00006. eCollection 2012.
Sex pheromone production in most moths is initiated following pheromone biosynthesis activating neuropeptide receptor (PBANR) activation. PBANR was initially cloned from pheromone glands (PGs) of Helicoverpa zea and Bombyx mori. The B. mori PBANR is characterized by a relatively long C-terminus that is essential for ligand-induced internalization, whereas the H. zea PBANR has a shorter C-terminus that lacks features present in the B. mori PBANR critical for internalization. Multiple PBANRs have been reported to be concurrently expressed in the larval CNS of Heliothis virescens. In the current study, we sought to examine the prevalence of multiple PBANRs in the PGs of three moths and to ascertain their potential functional relevance. Multiple PBANR variants (As, A, B, and C) were cloned from the PGs of all species examined with PBANR-C the most highly expressed. Alternative splicing of the C-terminal coding sequence of the PBAN gene gives rise to the variants, which are distinguishable only by the length and composition of their respective C-terminal tails. Transient expression of fluorescent PBANR chimeras in insect cells revealed that PBANR-B and PBANR-C localized exclusively to the cell surface while PBANR-As and PBANR-A exhibited varying degrees of cytosolic localization. Similarly, only the PBANR-B and PBANR-C variants underwent ligand-induced internalization. Taken together, our results suggest that PBANR-C is the principal receptor molecule involved in PBAN signaling regardless of moth species. The high GC content of the C-terminal coding sequence in the B and C variants, which makes amplification using conventional polymerases difficult, likely accounts for previous "preferential" amplification of PBANR-A like receptors from other species.
大多数飞蛾的性信息素产生是在性信息素生物合成激活神经肽受体（PBANR）激活后开始的。PBANR 最初是从棉铃虫和家蚕的性信息素腺（PG）中克隆出来的。B. mori PBANR 的特点是 C 端相对较长，这对于配体诱导的内化是必不可少的，而 H. zea PBANR 的 C 端较短，缺乏 B. mori PBANR 中对内化至关重要的特征。据报道，多个 PBANRs 同时在 Heliothis virescens 的幼虫中枢神经系统中表达。在目前的研究中，我们试图研究多个 PBANRs 在三种飞蛾的 PG 中的普遍性，并确定它们的潜在功能相关性。从所有检查的物种的 PG 中克隆出多个 PBANR 变体（As、A、B 和 C），其中 PBANR-C 的表达量最高。PBAN 基因 C 末端编码序列的选择性剪接产生了这些变体，它们只能通过各自 C 末端尾部的长度和组成来区分。在昆虫细胞中瞬时表达荧光 PBANR 嵌合体表明，PBANR-B 和 PBANR-C 仅定位于细胞膜表面，而 PBANR-As 和 PBANR-A 则表现出不同程度的细胞质定位。同样，只有 PBANR-B 和 PBANR-C 变体经历了配体诱导的内化。总之，我们的结果表明，无论飞蛾种类如何，PBANR-C 都是参与 PBAN 信号转导的主要受体分子。B 和 C 变体的 C 末端编码序列中的高 GC 含量使得使用常规聚合酶进行扩增变得困难，这可能解释了以前从其他物种中“优先”扩增 PBANR-A 样受体的原因。
