Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional Irapuato, Guanajuato, México.
Front Plant Sci. 2012 Aug 24;3:191. doi: 10.3389/fpls.2012.00191. eCollection 2012.
Upstream open reading frames (uORFs) are common in eukaryotic transcripts, but those that encode conserved peptides occur in less than 1% of transcripts. The peptides encoded by three plant conserved peptide uORF (CPuORF) families are known to control translation of the downstream ORF in response to a small signal molecule (sucrose, polyamines, and phosphocholine). In flowering plants, transcription factors are statistically over-represented among genes that possess CPuORFs, and in general it appeared that many CPuORF genes also had other regulatory functions, though the significance of this suggestion was uncertain (Hayden and Jorgensen, 2007). Five years later the literature provides much more information on the functions of many CPuORF genes. Here we reassess the functions of 27 known CPuORF gene families and find that 22 of these families play a variety of different regulatory roles, from transcriptional control to protein turnover, and from small signal molecules to signal transduction kinases. Clearly then, there is indeed a strong association of CPuORFs with regulatory genes. In addition, 16 of these families play key roles in a variety of different biological processes. Most strikingly, the core sucrose response network includes three different CPuORFs, creating the potential for sophisticated balancing of the network in response to three different molecular inputs. We propose that the function of most CPuORFs is to modulate translation of a downstream major ORF (mORF) in response to a signal molecule recognized by the conserved peptide and that because the mORFs of CPuORF genes generally encode regulatory proteins, many of them centrally important in the biology of plants, CPuORFs play key roles in balancing such regulatory networks.
上游开放阅读框 (uORF) 在真核转录物中很常见，但编码保守肽的 uORF 不到转录物的 1%。已知三种植物保守肽 uORF (CPuORF) 家族编码的肽可控制下游 ORF 的翻译，以响应小分子信号分子（蔗糖、多胺和磷酸胆碱）。在开花植物中，转录因子在具有 CPuORF 的基因中统计上过度表达，并且通常看来，许多 CPuORF 基因也具有其他调节功能，尽管这一建议的意义尚不确定 (Hayden 和 Jorgensen, 2007)。五年后，文献提供了更多关于许多 CPuORF 基因功能的信息。在这里，我们重新评估了 27 个已知 CPuORF 基因家族的功能，发现其中 22 个家族具有各种不同的调节作用，从转录控制到蛋白质周转，从小分子信号到信号转导激酶。显然，CPuORF 确实与调节基因密切相关。此外，这些家族中的 16 个家族在各种不同的生物学过程中发挥关键作用。最引人注目的是，核心蔗糖反应网络包括三个不同的 CPuORF，为响应三种不同的分子输入对网络进行复杂的平衡创造了潜力。我们提出，大多数 CPuORF 的功能是调节保守肽识别的信号分子下游主要 ORF (mORF) 的翻译，并且由于 CPuORF 基因的 mORF 通常编码调节蛋白，它们中的许多在植物生物学中至关重要，CPuORF 在平衡这些调节网络方面发挥着关键作用。
