Pastén-Hidalgo Karina, Hernández-Rivas Rosaura, Roa-Espitia Ana Lilia, Sánchez-Gutiérrez Manuel, Martínez-Pérez Francisco, Monrroy Alma Olivia, Hernández-González Enrique O, Mújica Adela
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional No. 2508 (CINVESTAV-IPN), PC 07360, México, DF, México.
Reproduction. 2008 Jul;136(1):41-51. doi: 10.1530/REP-07-0300. Epub 2008 Apr 4.
Successful fertilization requires gametes to complete several stages, beginning with maturation and transport along the male and female reproductive tracts and ending with the interaction between the sperm and the egg. This last step involves sperm-egg adhesion and membrane fusion. ADAMs (disintegrin and metalloprotease domain proteins) are a family of membrane-anchored glycoproteins that are thought to play diverse roles in cell-cell adhesion through their interaction with integrins. This study analyzes the presence, location, processing, and possible role of ADAM15 in mouse sperm. The presence of ADAM15 in mouse spermatozoa was detected by Western blotting, which revealed that ADAM15 is post-translationally processed, during epididymal sperm maturation and the acrosome reaction. The 35 kDa antigen present in the acrosome-reacted sperm is the last proteolytic product of the 110/75 kDa ADAM15 found in non-capacitated sperm. This 35 kDa protein contains the disintegrin domain. By indirect immunofluorescence, ADAM15 was identified in the acrosomal region and along the flagellum of mouse spermatozoa. In acrosome-reacted sperm, ADAM15 was lost from the acrosomal region, but remained diffusely distributed throughout the head and flagellum. Furthermore, the ADAM15 disintegrin domain (RPPTDDCDLPEF) partially inhibited fusion and almost completely inhibited sperm-oolemma adhesion. In conclusion, our data indicate that ADAM15 is present in the testis and in spermatozoa from the caput, corpus, and cauda epididymis, as well as in non-capacitated and acrosome-reacted gametes. Results also indicate that ADAM15 is processed during epididymal maturation and acrosome reaction and that it may play a role during sperm-egg binding.
成功受精需要配子完成几个阶段，从成熟并沿雄性和雌性生殖道运输开始，到精子与卵子相互作用结束。最后这一步涉及精卵黏附与膜融合。ADAMs（解整合素和金属蛋白酶结构域蛋白）是一类膜锚定糖蛋白，被认为通过与整合素相互作用在细胞间黏附中发挥多种作用。本研究分析了ADAM15在小鼠精子中的存在情况、定位、加工过程及可能的作用。通过蛋白质免疫印迹法检测到小鼠精子中存在ADAM15，结果显示ADAM15在附睾精子成熟和顶体反应过程中进行了翻译后加工。顶体反应精子中存在的35 kDa抗原是未获能精子中110/75 kDa ADAM15的最后蛋白水解产物。这种35 kDa蛋白含有解整合素结构域。通过间接免疫荧光法，在小鼠精子的顶体区域和鞭毛上鉴定出了ADAM15。在顶体反应的精子中，ADAM15从顶体区域消失，但仍弥散分布于整个头部和鞭毛。此外，ADAM15解整合素结构域（RPPTDDCDLPEF）部分抑制了融合，并几乎完全抑制了精子与卵细胞膜的黏附。总之，我们的数据表明ADAM15存在于睾丸以及附睾头、体、尾的精子中，也存在于未获能和顶体反应的配子中。结果还表明ADAM15在附睾成熟和顶体反应过程中被加工，并且它可能在精卵结合过程中发挥作用。
