casein-kinase-ii and Infertility--Male

Protein interacting with C kinase 1 (PICK1) is a peripheral membrane protein involved in protein trafficking, a function that has been well characterized in neurons. Here, we report that male mice deficient in PICK1 are infertile and have a phenotype resembling the human disease globozoospermia. The primary defect in the testes of Pick1-knockout mice was fragmentation of acrosomes in the early stages of spermiogenesis. This fragmentation was followed by defects in nuclear elongation and mitochondrial sheath formation, leading to round-headed sperm, reduced sperm count, and severely impaired sperm motility. We found that PICK1 interacted with Golgi-associated PDZ- and coiled-coil motif-containing protein (GOPC) and the primary catalytic subunit of protein kinase 2 (CK2alpha'), proteins whose deficiencies lead to globozoospermia in mice. PICK1 was highly expressed in round spermatids and localized to Golgi-derived proacrosomal granules. GOPC colocalized with PICK1 in the Golgi region and facilitated formation of PICK1-positive clusters. Furthermore, there was an increase in apoptosis in the seminiferous tubules of Pick1-/- mice, a phenotype also seen in CK2alpha'-deficient mice. Our results suggest that PICK1 is involved in vesicle trafficking from the Golgi apparatus to the acrosome and cooperates with other proteins such as GOPC and CK2alpha' in acrosome biogenesis.

Topics: Acrosome; Adaptor Proteins, Signal Transducing; Animals; Carrier Proteins; Casein Kinase II; Cell Cycle Proteins; Disease Models, Animal; Epididymis; Golgi Apparatus; Golgi Matrix Proteins; Humans; Infertility, Male; Intracellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron, Transmission; Models, Biological; Nuclear Proteins; Protein Interaction Mapping; Rats; Rats, Sprague-Dawley; Spermatogenesis; Spermatozoa

Globozoospermia is a severe form of teratozoospermia characterized by round-headed sperm with an absence of acrosomes. Family cases of globozoopermia suggest that this pathology has genetic origins, but the mode of inheritance remains unknown. So far, no responsible genes have been identified. Recently, a mouse lacking the casein kinase IIalpha' (encoded by the Csnk2a2 gene) was described. This mutant mouse presents a single phenotype reminiscent of that seen in human globozoospermia. Interestingly, the fission yeast orthologue (orb5) exhibits, when mutated, a spherical phenotype. Casein kinase II is a heterotetramer, composed of two catalytic subunits alpha or alpha' and two regulatory beta subunits (encoded by the Csnk2b gene).. Based on the evolution conservation, phenotypes observed in mouse and yeast mutant and the structure of casein kinase II, we analysed Csnk2a2 and Csnk2b genes in six patients with globozoospermia and 10 fertile controls. Genomic DNA was extracted from peripheral blood and PCR was performed to amplify Csnk2a2 and Csnk2b genes before sequencing.. No mutation was identified among these six patients. Further work is needed, with a larger patient data set, to identify putative genes involved in this form of male infertility.

Topics: Adult; Casein Kinase II; Gene Expression Regulation; Humans; Infertility, Male; Male; Mutation; Polymerase Chain Reaction; Reference Values; Sequence Analysis, DNA; Spermatozoa

We describe an approach to search for candidate genes for male infertility using the two human genome databases: the public University of California at Santa Cruz (UCSC) and private Celera databases which list known and predicted gene sequences and provide related information such as gene function, tissue expression, known mutations and single nucleotide polymorphisms (SNPs).. To demonstrate this in silico research, the following male infertility candidate genes were selected: (1) human BOULE, mutations of which may lead to germ cell arrest at the primary spermatocyte stage, (2) mutations of casein kinase 2 alpha genes which may cause globozoospermia, (3) DMR-N9 which is possibly involved in the spermatogenic defect of myotonic dystrophy and (4) several testes expressed genes at or near the breakpoints of a balanced translocation associated with hypospermatogenesis. We indicate how information derived from the human genome databases can be used to confirm these candidate genes may be pathogenic by studying RNA expression in tissue arrays using in situ hybridization and gene sequencing.. The paper explains the new approach to discovering genetic causes of male infertility using information about the human genome.

Topics: Casein Kinase II; Chromosome Mapping; Databases, Genetic; Genetic Techniques; Genome, Human; Humans; In Situ Hybridization; Infertility, Male; Male; Mutation; Protein Serine-Threonine Kinases; Proteins; RNA-Binding Proteins; RNA, Messenger

Protein kinase casein kinase II (Ck2) is a cyclic-AMP and calcium-independent serine-threonine kinase that is composed of two catalytic subunits (alpha and alpha') and two regulatory beta-subunits. Ck2 is not a casein kinase in vivo, but over 100 substrates are known. The highly conserved amino acid sequences of its subunits and their broad expression suggest that Ck2 may have a fundamental role in cell function. Ck2 has been implicated in DNA replication, regulation of basal and inducible transcription, translation and control of metabolism. The Ck2alpha and Ck2alpha' isoforms (products of the genes Csnk2a1 and Csnk2a2, respectively) are highly homologous, but the reason for their redundancy and evolutionary conservation is unknown. We find here that Csnk2a2 is preferentially expressed in late stages of spermatogenesis, and male mice in which Csnk2a2 has been disrupted are infertile, with oligospermia and globozoospermia ('round-headed' spermatozoa). This is the first demonstration of a unique role for a Ck2 isoform in development. The primary spermatogenic defect in Csnk2a2-/- testis is a specific abnormality of anterior head shaping of elongating spermatids; this is the first defined gene that regulates sperm head morphogenesis. As the germ cells differentiate, they are capable of undergoing chromatin condensation, although many abnormal cells are deleted through apoptosis or Sertoli cell phagocytosis. The few that survive to populate the epididymis exhibit head abnormalities similar to those described in human globozoospermia, thus Csnk2a2 may be a candidate gene for these inherited syndromes.

Topics: Animals; Apoptosis; Casein Kinase II; Catalytic Domain; Chromatin; DNA; Female; Heterozygote; In Situ Nick-End Labeling; Infertility, Male; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron; Models, Genetic; Nicotiana; Plants, Toxic; Protein Serine-Threonine Kinases; Recombination, Genetic; RNA, Messenger; Spermatogenesis; Spermatozoa; Testis; Tissue Distribution