Acrosome Biogenesis in the Hamster: DISCUSSION(5)
Immunoblotting and immunofluorescence studies have also identified antigenic changes in acrosomal proteins of guinea pig and mouse late spermatids and spermatozoa consistent with intra-acrosomal protein processing. We have been unable to demonstrate any carbohydrates associated with AM22 or AM29 by lectin staining of Western blots (unpublished data), so the specific nature of potential posttranslational modifications occurring during the late stages of spermiogenesis needs identification. buy asthma inhalers
AM22 and AM29 assemble into stable matrix elements that are specifically associated with the fusigenic domains of the outer acrosomal membrane. The mechanisms that establish this specific interaction are not known, but it probably reflects specific protein-protein interactions between matrix polypeptides and proteins localized to the luminal surface of the outer acrosomal membrane. Different elements of the acrosomal matrix display specific fates during acrosomal exocytosis. The matrix assembly associated with the outer acrosomal membrane appears particularly stable and remains associated with the hybrid membranes after the acrosome reaction . Thus it is possible that the role of these matrix elements is not limited to regulating hydrolase distribution and release during the acrosome reaction but they could also function in the membrane fusion events or in sperm-zona interactions. These potential functions as well as identification of specific interactions between the acrosomal matrix and the outer acrosomal membrane will be addressed in future studies.