2001 Fiscal Year Final Research Report Summary
Identification and analysis of temperature-sensitive proteins : the, temperature dependent immobilization of fowl spermatozoa at body temperature as a model
| Project/Area Number |
11460130
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied animal science
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| Research Institution | Miyazaki University |
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Principal Investigator |
ASHIZAWA Koji Miyazaki Univ., Fac. Agric., Professor, 農学部, 教授 (60128353)
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| Co-Investigator(Kenkyū-buntansha) |
TSUZUKI Yasuhiro Miyazaki Univ., Fac. Agric., Assist. Prof., 農学部, 助手 (00236928)
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| Project Period (FY) |
1999 – 2001
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| Keywords | spermatozoa / flagellar movement / inhibitor / regulation of motility / phosphorvlation / dephosphorvlation / signal transduction / activator |
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| Research Abstract |
The motility of spermatozoa is controlled by phosphorylation-dephosphorylation of specific proteins existing in flagella. Protein phosphorylation is mediated by protein kinases and dephosphorylation is mediated by protein phosphatases. Although it has been proposed that the reversible temperature-dependent immobilization of fowl spermatozoa is related to the activation of protein phosphatase, it has not been clarified in detail yet. The motility of spermatozoa in TES/NaCl buffer with or without IPVL at 40 ℃ was almost negligible, due to the temperature-dependent immobilization of fowl spermatozoa. However, sperm motility was restored at 40 ℃ following the addition of calyculin A, but not by fenvalerate or deltamethrin. The AR was stimulated by IPVL extracts at 40 ℃, but only in the presence of Ca^<2+>, calyculin A, fenvalerate or deltamethrin, the latter three phosphatase inhibitors stimulating the AR in a dose-dependent manner in the range of 10-1000 nM. At 30 ℃, the effects of PP2A activators (C2 - Ceramide and C6 - Ceramide) on the motility of spermatozoa, were not clear. At 40 ℃, both intact and demembranated sperm motility were almost negligible, regardless of the presence of Ceramides. Furthermore, stimulation of motility by Ca^<2+> was gradually inhibited following the addition of Ceramides. The same tendency was observed even when calyculin A was used instead of Ca^<2+>.
These results suggest that Ca^<2+> may act via activation of protein phosphorylation pathways and that the Ca^<2+> -activated intracellular molecular mechanisms for the regulation of AR are different from those for restoration of sperm motility ; i.e., protein dephosphorylation by PP2B, in addition to PP1 and/or PP2A, in the former and PP1 and/or PP2A alone in the latter case.
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Research Products
(8 results)
