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Kinases as targets for chemical modulators: Structural aspects and their role in spermatogenesis.

ABSTRACT: Protein phosphorylation and de-phosphorylation events are crucial in deciding the fate of cells. They regulate cellular growth, differentiation and cell death, and kinases are the key players of these events. The members of ser/thr kinases and tyrosine kinases form the majority of protein kinase family, exerting their regulatory mechanism in almost all cells. In testis, they impact signal transduction events, regulate all stages of sperm development from mitosis through fertilization. Understanding the function of these kinases at the structural level and studying their interactions with inhibitors can help in understanding the machinery of spermatogenesis. In view of this, we have reviewed some of the prominent kinases that are known to play a role in spermatogenesis. A better understanding of the impacts of kinase inhibition on spermatogenesis should aid in the interpretation of lesions and hopefully further the development of more efficient and potent drug candidates.

SUBMITTER: Jenardhanan P

PROVIDER: S-EPMC4581050 | biostudies-literature | 2014 May-Aug

REPOSITORIES: biostudies-literature

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Kinases as targets for chemical modulators: Structural aspects and their role in spermatogenesis.

Jenardhanan Pranitha P Mathur Premendu P PP

Spermatogenesis 20140501 2

Protein phosphorylation and de-phosphorylation events are crucial in deciding the fate of cells. They regulate cellular growth, differentiation and cell death, and kinases are the key players of these events. The members of ser/thr kinases and tyrosine kinases form the majority of protein kinase family, exerting their regulatory mechanism in almost all cells. In testis, they impact signal transduction events, regulate all stages of sperm development from mitosis through fertilization. Understand ...[more]

PMID: 26413395

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Project description:Spermatogenesis is a complex cell differentiation process that includes marked genetic, cellular, functional and structural changes. It requires tight regulation, because disturbances in any of the spermatogenic processes would lead to fertility deficiencies as well as disorders in offspring. To increase our knowledge of signal transduction during sperm development, we carried out a large-scale identification of the phosphorylation events that occur in the human male gonad. Metal oxide affinity chromatography using TiO2 combined with LC-MS/MS was conducted to profile the phosphoproteome of adult human testes with full spermatogenesis. A total of 8187 phosphopeptides derived from 2661 proteins were identified, resulting in the most complete report of human testicular phosphoproteins to date. Phosphorylation events were enriched in proteins functionally related to spermatogenesis, as well as to highly active processes in the male gonad, such as transcriptional and translational regulation, cytoskeleton organization, DNA packaging, cell cycle and apoptosis. Moreover, 174 phosphorylated kinases were identified. The most active human protein kinases in the testis were predicted both by the number of phosphopeptide spectra identified and the phosphorylation status of the kinase activation loop. The potential function of cyclin-dependent kinase 12 (CDK12) and p21-activated kinase 4 (PAK4) has been explored by in silico, protein-protein interaction analysis, immunodetection in testicular tissue, and a functional assay in a human embryonal carcinoma cell line. The colocalization of CDK12 with Golgi markers suggests a potential crucial role of this protein kinase during sperm formation. PAK4 has been found expressed in human spermatogonia, and a role in embryonal carcinoma cell response to apoptosis has been observed. Together, our protein discovery analysis confirms that phosphoregulation by protein kinases is highly active in sperm differentiation and opens a window to detailed characterization and validation of potential targets for the development of drugs modulating male fertility and tumor behavior.

Project description:Spermatogenesis is a complex cell differentiation process that includes marked genetic, cellular functional and structural changes. It requires tight regulation, since disturbances in any of the spermatogenic stages would lead to fertility deficiencies. In order to increase our knowledge of signal transduction during sperm development, we carried out a large-scale identification of the phosphorylation events that occur in the human gonad. Metal oxide affinity chromatography using TiOx combined with LC-MS/MS was conducted to profile the phosphoproteome of human testes with full spermatogenesis. A total of 8187 phosphopeptides derived from 2661 proteins were identified, resulting in the most complete report of human testicular phosphoproteins to date. Phosphorylation events were enriched in proteins functionally related to spermatogenesis, as well as to highly active processes in the male gonad, such as transcriptional and translational regulation, cytoskeleton organization, DNA packaging, cell cycle and apoptosis. Moreover, 174 phosphorylated kinases were identified. The most active and abundant human protein kinases in the testis were predicted both by the phosphorylation status of the kinase activation loop and the number of phosphopeptide spectra identified. The potential function of two of those kinases, cyclin-dependent kinase 12 (CDK12) and p21-activated kinase 4(PAK4), has been explored by protein-protein interaction analysis, immunodetection in human and mouse testicular tissue, and functional assay in a human embryonal carcinoma cell line. The co-localization of CDK12 with Golgi markers and probably pro-acrosomal vesicles suggests a potential crucial role of this protein kinase in sperm formation. PAK4 expression has been found limited to human spermatogonia, and a role in embryonal carcinoma cell response to apoptosis has been observed. Together, our data confirm that phosphoregulation by protein kinases is highly active in sperm differentiation, and open a window to detailed characterization and validation of potential targets for the development of drugs modulating male fertility, and tumor behavior.

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Dataset Information

Kinases as targets for chemical modulators: Structural aspects and their role in spermatogenesis.

Publications

Kinases as targets for chemical modulators: Structural aspects and their role in spermatogenesis.

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