CABYR binds to AKAP3 and Ropporin in the human sperm fibrous sheath

Calcium-binding tyrosine phosphorylation-regulated protein （CABYR） is a highly polymorphic calcium-binding tyrosine- and serine-/threonine-phosphorylated fibrous sheath （FS） protein involved in capacitation. A putative domain （amino acids 12-48） homologous to the regulatory subunit of type II cAMP-dependent protein kinase A （RII） dimerisation and A kinase-anchoring protein （AKAP）-binding domains of protein kinase A at the N-terminus suggests that CABYR may self-assemble and bind to AKAPs. Moreover, there is evidence that CABYR has limited interaction with AKAPs. However, further evidence and new relationships between CABYR and other FS proteins, including AKAPs, will be helpful in understanding the basic physiology of FS. In this study, a new strategy for co-immunoprecipitation of insoluble proteins, as well as the standard co-immunoprecipitation method in combination with mass spectrometry and western blot, was employed to explore the relationship between CABYR, AKAP3 and Ropperin. The results showed that AKAP3 was co.immunoprecipitated with CABYR by the anti-CABYR-A polyclonal antibody, and, conversely, CABYR was also co.immunoprecipitated with AKAP3 by the anti-AKAP3 polyclonal antibody. Another RIl-like domain containing protein, Ropporin, was also co-immunoprecipitated with CABYR, indicating that Ropporin is one of CABYR＇s binding partners. The interactions between CABYR, AKAP3 and Ropporin were confirmed by yeast two-hybrid assays. Further analysis showed that CABYR not only binds to AKAP3 by its RII domain but binds to Ropporin through other regions besides the RIl-like domain. This is the first demonstration that CABYR variants form a complex not only with the scaffolding protein AKAP3 but also with another Rll-like domain-containing protein in the human sperm FS.

Porta-caval fibrous connections-the lesser-known structure of intrahepatic connective-tissue framework:A unified view of liver extracellular matrix

Knowledge about the connective-tissue framework of the liver is not systematized,the terminology is inconsistent and some perspectives on the construction of the hepatic matrix components are contradictory.In addition,until the last two decades of the 20th century,the connective-tissue sheaths of the portal tracts and the hepatic veins were considered to be independent from each other in the liver and that they do not make contact with each other.The results of the research carried out by Professor Shalva Toidze and his colleagues started in the 1970s in the Department of Operative Surgery and Topographic Anatomy at the Tbilisi State Medical Institute have changed this perception.In particular,Chanukvadze I showed that in some regions where they intersect with each other,the connective tissue sheaths of the large portal complexes and hepatic veins fuse.The areas of such fusion are called porta-caval fibrous connections(PCFCs).This opinion review aims to promote a systematic understanding of the hepatic connective-tissue skeleton and to demonstrate the hitherto underappreciated PCFC as a genuine structure with high biological and clinical significance.The components of the liver connective-tissue framework—the capsules,plates,sheaths,covers—are described,and their intercommunication is discussed.The analysis of the essence of the PCFC and a description of its various forms are provided.It is also mentioned that analogs of different forms of PCFC are found in different mammals.

Homogeneous Microscopic Abnormalities in Sperm Morphology and Immotility as A Cause of Male Infertility

Objective To study the identification of the cause of specific sperm abnormatities. Methods Two adult men with specific alterations in sperm morphology causing 100% immobility were included in this study. The study of sperm used： transmission electron microscopy （both patients）; apoptotic markers, DNA fragmentation test and fluorescence in-situ hybridization （patient 1） and immunoeytochemistry study of sperm flagellum using anti-β tubulin antibodies and ciliary activity test （patient 2）.Results Increased DNA fragmentation （52.6%） and apoptosis biomarkers were detected in patient 1, and loss of the central pair of mierotubules in patient 2 （‘9＋0＇ axoneme）; the nasal ciliary activity was normal. Conclusion Results suggest an apoptotic origin of the abnormalities in the sperm from patient 1 and dysplasia of the fibrous sheath in patient 2.