Department of Biological Sciences, University of Toledo, Toledo, OH 43607, USA.
Cells. 2019 Aug 5;8(8):841. doi: 10.3390/cells8080841.
Insects and mammals have atypical centrioles in their sperm. However, it is unclear how these atypical centrioles form. sperm has one typical centriole called the giant centriole (GC) and one atypical centriole called the proximal centriole-like structure (PCL). During early sperm development, centriole duplication factors such as Ana2 and Sas-6 are recruited to the GC base to initiate PCL formation. The centriolar protein, Poc1B, is also recruited at this initiation stage, but its precise role during PCL formation is unclear. Here, we show that Poc1B recruitment was dependent on Sas-6, that Poc1B had effects on cellular and PCL Sas-6, and that Poc1B and Sas-6 were colocalized in the PCL/centriole core. These findings suggest that Sas-6 and Poc1B interact during PCL formation. Co-overexpression of Ana2 and Sas-6 induced the formation of ectopic particles that contained endogenous Poc1 proteins and were composed of PCL-like structures. These structures were disrupted in mutant flies, suggesting that Poc1 proteins stabilize the PCL-like structures. Lastly, Poc1B and Sas-6 co-overexpression also induced the formation of PCL-like structures, suggesting that they can function together during the formation of the PCL. Overall, our findings suggest that Poc1B and Sas-6 function together during PCL formation.
昆虫和哺乳动物的精子中存在非典型的中心粒。然而，这些非典型中心粒是如何形成的尚不清楚。精子中有一个典型的中心粒，称为巨大中心粒（GC），还有一个非典型的中心粒样结构，称为近端中心粒样结构（PCL）。在早期精子发生过程中，中心体复制因子如 Ana2 和 Sas-6 被招募到 GC 基部，启动 PCL 的形成。中心粒蛋白 Poc1B 也在这个起始阶段被招募，但它在 PCL 形成过程中的精确作用尚不清楚。在这里，我们表明 Poc1B 的募集依赖于 Sas-6，Poc1B 对细胞和 PCL Sas-6 有影响，并且 Poc1B 和 Sas-6 在 PCL/中心粒核心中发生共定位。这些发现表明 Sas-6 和 Poc1B 在 PCL 形成过程中相互作用。Ana2 和 Sas-6 的共过表达诱导形成含有内源性 Poc1 蛋白的异位颗粒，这些颗粒由 PCL 样结构组成。在 突变体果蝇中，这些结构被破坏，表明 Poc1 蛋白稳定 PCL 样结构。最后，Poc1B 和 Sas-6 的共过表达也诱导了 PCL 样结构的形成，表明它们在 PCL 的形成过程中可以共同发挥作用。总之，我们的研究结果表明，Poc1B 和 Sas-6 在 PCL 形成过程中共同发挥作用。
