Identification of Oocyte-Specific Diva-Associated Proteins using Mass Spectrometry

Mass Spectrometry를 이용한 난자 특이적인 Diva와 상호작용하는 단백질의 동정

  • Yoon, Se-Jin (CHA Research Institute, Fertility Center, CHA General Hospital) ;
  • Kim, Jung-Woong (Laboratory of Molecular Biology, Department of Biological Science, College of Natural Sciences, Chung-Ang University) ;
  • Choi, Kyung-Hee (Laboratory of Molecular Biology, Department of Biological Science, College of National Sciences, Chung-Ang University) ;
  • Lee, Sook-Hwan (CHA Research Institute, Fertility Center, CHA General Hospital) ;
  • Lee, Kyung-Ah (CHA Research Institute, Fertility Center, CHA General Hospital)
  • 윤세진 (차병원 여성의학연구소) ;
  • 김정웅 (중앙대학교 자연과학대학 생명과학과) ;
  • 최경희 (중앙대학교 자연과학대학 생명과학과) ;
  • 이숙환 (차병원 여성의학연구소) ;
  • 이경아 (차병원 여성의학연구소)
  • Published : 2006.09.30

Abstract

Objective: We previously described that Diva is highly expressed in matured metaphase II (MII) oocytes compared to immature germinal vesicle (GV) oocytes in mouse. We report here that the expression of Diva transcript as well as protein is oocyte-specific. To elucidate its physiological role in oocyte, the binding partner(s) of Diva has been identified by using immunoprecipitation (IP) followed by Mass Spectrometry. Methods: NIH/3T3 cells were transiently transfected for 24 h with either empty vector for control or FLAG-tagged mouse Diva construct, and IP was performed with anti-FLAG antibody. The immuno-isolated complexes were resolved by SDS-PAGE on a 12% gel followed by Coomassie Blue staining. For in-gel digestion, 15 bands of interest were excised manually and digested with trypsin. All mass spectra were acquired at a positive reflector mode by a 4700 Proteomics Analyzer (Applied Biosystems, Framingham, MA). Proteins were identified by searching the NCBI nonredundant database using MASCOT Peptide Mass Fingerprint software (Matrixscience, London). Results: Diva-associated complexes were formed in FLAG-tagged mouse Diva-overexpressed NIH/3T3 cells via IP using anti-FLAG-conjugated beads. Among the excised 15 bands, actin and actin-binding proteins such as tropomyosin, tropomodulin 3, and ${\alpha}$-actinin were identified. Binding between Diva and actin or tropomyosin was confirmed by IP followed by Western blot analysis. Both bindings were also detected endogenously in mouse ovaries, indicating that Diva works with actin and tropomyosin. Conclusions: This is the first report that immuno-isolated Diva-associated complexes are related to actin filament of the cytoskeletal system. When we consider the association of Diva with actin and tropomyosin, oocyte-specific Diva may play a role in modulating the cytoskeletal system during oocyte maturation.

목적: 본 연구진은 난자성숙 과정의 조절 기작을 규명하기 위하여 생쥐의 미성숙 난자와 성숙난자에서 차이 나게 발현하는 유전자의 목록을 얻은 바 있다. 이들 유전자 중에서 Bcl-2 homolog인 Diva 유전자가 난자에 특이적으로 발현함을 본 연구를 통해 규명하였는데 이러한 Diva의 기능을 밝혀내기 위하여 immunoprecipitation (IP)과 Mass Spectrometry (MS)를 이용하여 Diva와 결합하여 상호작용하는 단백질을 동정하고자 하였다. 연구방법: NIH/3T3 세포주에 Diva를 encoding하는 pCMV-FLAG-Diva를 24 시간 동안 과발현 시키고 대조군으로는 유전자 없는 pCMV-FLAG empty vector를 transfection 하였다. FLAG에 특이적인 항체로 IP하여 Diva와 결합하는 면역복합체를 형성하게 한 후 이를 12% SDS-polyacrylamide gel 상에서 전기 영동하였고 Coomassie Blue 염색을 통해 단백질 발현양상을 관찰하였다. 대조군에서는 관찰되지 않으면서 Diva 유전자가 발현하는 실험군에서만 확인되는 밴드를 오려내어 trypsin을 사용하여 in-gel digestion 한 후 MS 분석을 시행하였다. 모든 mass spectra는 4700 Proteomics Analyzer (Applied Biosystems, Framingham, MA)에 의해 positive reflector mode에서 얻어졌다. 이렇게 얻어진 단백질들은 MASCOT Peptide Mass Fingerprint software (Matrixscience, London)을 이용하여 NCBI nonredundant database를 찾아서 동정하였다. 결과: Diva를 과발현하는 세포주에서만 관찰되는 15개 밴드에 대한 MS/MS 분석 결과, Diva와 결합하는 단백질로서 actin과 그 외에 ${\alpha}$-actinin, tropomyosin, tropomodulin 3 등의 actin-binding 단백질을 동정하였다. Diva를 과발현하는 NIH/3T3 세포주에서 면역 복합체를 형성하는 actin과 tropomyosin이 실제 난소 조직에서도 Diva와 결합하는지 IP와 Western blot을 통해 확인한 결과, actin과 tropomyosin 모두 Diva와 결합함을 확인함으로써, Diva는 이 두 단백질과 난소에서 상호작용함을 알 수 있었다. 결론: 본 연구는 Diva와 결합하여 상호작용하는 단백질들이 cytoskeletal system의 actin filament와 관계 있음을 규명한 최초의 보고이다. Diva가 actin과 tropomyosin과 결합하는 것을 고려해볼때, 난자 특이적인 Diva는 아마도 난자성숙 동안에 cytoskeletal system 을 조절하는 역할을 할 것으로 사료된다.

Keywords

Acknowledgement

Supported by : 보건복지부

References

  1. Yoon SJ, Chung HM, Cha KY, Kim NH, Lee KA. Identification of differential gene expression in germinal vesicle vs. metaphase II mouse oocytes by using annealing control primers. Fertil Steril 2005; 83 Suppl 1: 1293-6 https://doi.org/10.1016/j.fertnstert.2004.09.037
  2. Barnes FL, Sirard MA. Oocyte maturation. Semin Reprod Med 2000; 18: 123-31 https://doi.org/10.1055/s-2000-12551
  3. Sirard MA. Resumption of meiosis: mechanism involved in meiotic progression and its relation with developmental competence. Theriogenology 2001; 55: 1241-54 https://doi.org/10.1016/S0093-691X(01)00480-0
  4. Chao DT, Korsmeyer SJ. BCL-2 family: regulators of cell death. Annu Rev Immunol 1998; 16: 395-419 https://doi.org/10.1146/annurev.immunol.16.1.395
  5. Adams JM, Cory S. Life-or-death decisions by the Bel-2 protein family. Trends Biochem Sci 2001; 26: 61-6 https://doi.org/10.1016/S0968-0004(00)01740-0
  6. Inohara N, Gourley TS, Carrio R, Muniz M, Merino J, Garcia I, et al. Diva, a Bcl-2 homologue that binds directly to Apaf-1 and induces BH3-independent cell death. J Biol Chem 1998; 273: 32479-86 https://doi.org/10.1074/jbc.273.49.32479
  7. Song Q, Kuang Y, Dixit VM, Vincenz C. Boo, a novel negative regulator of cell death, interacts with Apaf-1. EMBO J 1999; 18: 167-78 https://doi.org/10.1093/emboj/18.1.167
  8. Lee R, Chen J, Matthews CP, McDougall JK, Neiman PE. Characterization of NR13-related human cell death regulator, Boo/Diva, in normal and cancer tissues. Biochim Biophys Acta 2001; 1520: 187-94 https://doi.org/10.1016/S0167-4781(01)00268-8
  9. Naumann D, Weit S, Wischhusen J, Weller M. Diva/Boo is a negative regulator of cell death in human glioma cells. FEBS Lett 2001; 505: 23-6 https://doi.org/10.1016/S0014-5793(01)02768-5
  10. Russell HR, Lee Y, Miller HL, Zhao J, McKinnon PJ. Murine ovarian development is not affected by inactivation of the bcl-2 family member diva. Mol Cell Biol 2002; 22: 6866-70 https://doi.org/10.1128/MCB.22.19.6866-6870.2002
  11. McGrath SA, Esquela AF, Lee SJ. Oocyte-specific expression of growth/differentiation factor-9. Mol Endocrinol 1995; 9: 131-6 https://doi.org/10.1210/me.9.1.131
  12. Ke N, Godzik A, Reed JC. Bcl-B, a novel Bcl-2 family member that differentially binds and regulates Bax and Bak. J Biol Chem 2001; 276: 12481-4 https://doi.org/10.1074/jbc.C000871200
  13. Tilly JL, Tilly Kl, Kenton ML, Johnson AL. Expression of members of the bcl-2 gene family in the immature rat ovary: equine chorionic gonadotropin-mediated inhibition of granulosa cell apoptosis is associated with decreased bax and constitutive bcl-2 and bcl-xlong messenger ribonucleic acid levels. Endocrinology 1995; 136: 232-41 https://doi.org/10.1210/en.136.1.232
  14. Kaipia A, Hsu SY, Hsueh AJ. Expression and function of a proapoptotic Bcl-2 family member Bcl-XL/Bcl-2-associated death promoter (BAD) in rat ovary. Endocrinology 1997; 138: 5497-504 https://doi.org/10.1210/en.138.12.5497
  15. Hsu SY, Kaipia A, McGee E, Lomeli M, Hsueh AJ. Bok is a pro-apoptotic Bcl-2 protein with restricted expression in reproductive tissues and heterodimerizes with selective anti-apoptotic Bcl-2 family members. Proc Natl Acad Sci USA 1997; 94: 12401-6 https://doi.org/10.1073/pnas.94.23.12401
  16. Leo CP, Hsu SY, Chun SY, Bae HW, Hsueh AJ. Characterization of the antiapoptotic Bcl-2 family member myeloid cell leukemia-1 (Mcl-1) and the stimulation of its message by gonadotropins in the rat ovary. Endocrinology 1999; 140: 5469-77 https://doi.org/10.1210/en.140.12.5469
  17. Hsueh AJ, Billig H, Tsafriri A. Ovarian follicle atresia: a hormonally controlled apoptotic process. Endocr Rev 1994; 15: 707-24
  18. Hsu SY, Hsueh AJ. Tissue-specific Bcl-2 protein partners in apoptosis: an ovarian paradigm. Physiol Rev 2000; 80: 593-614 https://doi.org/10.1152/physrev.2000.80.2.593
  19. Fields S, Song O. A novel genetic system to detect protein-protein interactions. Nature 1989; 340: 245-6 https://doi.org/10.1038/340245a0
  20. Cai Y, Jin J, Tomomori-Sato C, Sato S, Sorokina I, Parmely TJ, et al. Identification of new subunits of the multiprotein mammalian TRRAP/TIP60-containing histone acetyltransferase complex. J Biol Chem 2003; 278: 42733-6 https://doi.org/10.1074/jbc.C300389200
  21. Hayano T, Yanagida M, Yamauchi Y, Shinkawa T, Isobe T, Takahashi N. Proteomic analysis of human Nop56p-associated pre-ribosomal ribonucleoprotein complexes. J Biol Chem 2003; 278: 34309-19 https://doi.org/10.1074/jbc.M304304200
  22. Sun QY, Schatten H. Regulation of dynamic events by microfilaments during oocyte maturation and fertilization. Reproduction. 2006; 131: 193-205 https://doi.org/10.1530/rep.1.00847