High impact information on Spz1

• Reduction of endogenous Spz1 expression via RNA interference decreased cell proliferation in p19 embryonic carcinoma cells [1].
• High levels of Spz1 expression were detected in murine tumor cell lines and tumor samples of both human and Spz1 transgenic mice [1].
• Immunohistochemistry on wild type testis sections reveals a stage-specific expression pattern for Spz1 during spermatogenesis that appeared grossly abnormal in the testes of PP1cgamma mutant mice [2].
• Interaction between full-length Spz1 and PP1cgamma2 was verified by co-immunoprecipitation and co-localization experiments in COS-1 cells as well as gel-shift and sedimentation assays using whole testis lysates [2].
• These results imply that Spz1 plays an important regulatory role during spermatogenesis [3].

Biological context of Spz1

• Using this model, we were able to demonstrate that overexpression of Spz1 in the testis destroys tissue homeostasis at an early stage of spermatogenesis, which in turn induces apoptosis in germ cells and thus reduces male fertility [3].
• TSP1 had also a sequence homology with Spz 1 protein of mouse [4].

Anatomical context of Spz1

• These results suggest that cell proliferation in early spermatogenesis is critically regulated by multisignal pathways and unregulated cell proliferation at this stage, as induced by Spz1, leads to germ cell apoptosis [3].
• Spz1, a previously identified basic helix-loop-helix-leucine zipper (bHLH-Zip) transcription factor, is expressed specifically in the testis and epididymis of adult mice [3].
• Immunofluorescence staining detected Spz1 protein in the nuclei of LFG6 Leydig cells [5].

Other interactions of Spz1

• Further analysis showed that the expression of zygotically activated genes such as Interferon-gamma, Dub-1, Spz1, DD2106 (unknown gene), and DD2111 (unknown gene) were suppressed in NT embryos, suggesting that the cellular process involved in the nuclear reprogramming of somatic nucleus is not appropriately regulated [6].

Analytical, diagnostic and therapeutic context of Spz1

• In the testes of transgenic mice, Spz1 proteins were found to be overexpressed in both germ and somatic cells as determined by immunofluorescence staining [3].
• We identified that Spz1 is ectopically expressed in multiple tissues of transgenic male mice by Western blot analysis [3].
• The ability of Spz1 protein to bind to the bHLH consensus-binding site, the E-box, was confirmed by EMSA, and a 9-bp asymmetric target site was identified by random selection and PCR amplification [5].

References