TY - JOUR
T1 - A lysophosphoinositide-specific phospholipase C distinct from other phospholipase C families in rat brain
AU - Tsutsumi, Tomonari
AU - Kobayashi, Tetsuyuki
AU - Miyashita, Miho
AU - Watanabe, Shiro
AU - Homma, Yoshimi
AU - Okuyama, Harumi
PY - 1995
Y1 - 1995
N2 - Distinct phospholipase C activities capable of hydrolyzing lysophosphatidylinositol (lysoPI-PLC) or phosphatidylinositol (PI-PLC) have been demonstrated in rat brain membranes. Treatment of brain membranes with 1 M NaCl or 1% sodium cholate solubilized a majority of PI-PLC activity from the membranes, whereas a significant level of lysoPI-PLC activity still remained membrane-associated. Most of the lysoPI-PLC activity was recovered in a 0.5% sodium deoxycholate-0.25 M NaCl extract which contained only low levels of PI-PLC activity. Using the separated fractions, differences between lysoPI-PLC and the known PI-PLC isoforms were examined. A specific peptide inhibitor of PI-PLC, which was previously shown to interact with active site regions common to known PI-PLC isoforms, did not suppress the extracted lysoPI-PLC activity. Immunoblot analysis of both the lysoPI-PLC-rich and PI-PLC-rich fractions revealed that an antiserum against PI-PLCδ1 cross-reacted with other PI-PLC isoforms, but not significantly with lysoPI-PLC. Furthermore, lysoPI-PLC was more resistant to sulfhydryl reagents than was PI-PLC. Our results indicate that lysoPI-PLC is an enzyme distinct from PI-PLC and that lysoPI-PLC possesses a different active site than known PI-PLC isoforms.
AB - Distinct phospholipase C activities capable of hydrolyzing lysophosphatidylinositol (lysoPI-PLC) or phosphatidylinositol (PI-PLC) have been demonstrated in rat brain membranes. Treatment of brain membranes with 1 M NaCl or 1% sodium cholate solubilized a majority of PI-PLC activity from the membranes, whereas a significant level of lysoPI-PLC activity still remained membrane-associated. Most of the lysoPI-PLC activity was recovered in a 0.5% sodium deoxycholate-0.25 M NaCl extract which contained only low levels of PI-PLC activity. Using the separated fractions, differences between lysoPI-PLC and the known PI-PLC isoforms were examined. A specific peptide inhibitor of PI-PLC, which was previously shown to interact with active site regions common to known PI-PLC isoforms, did not suppress the extracted lysoPI-PLC activity. Immunoblot analysis of both the lysoPI-PLC-rich and PI-PLC-rich fractions revealed that an antiserum against PI-PLCδ1 cross-reacted with other PI-PLC isoforms, but not significantly with lysoPI-PLC. Furthermore, lysoPI-PLC was more resistant to sulfhydryl reagents than was PI-PLC. Our results indicate that lysoPI-PLC is an enzyme distinct from PI-PLC and that lysoPI-PLC possesses a different active site than known PI-PLC isoforms.
KW - Isozymes
KW - Lysophosphatidylinositol
KW - Phosphatidylinositol
KW - Phospholipase C
KW - Rat brain
UR - http://www.scopus.com/inward/record.url?scp=0028912204&partnerID=8YFLogxK
U2 - 10.1006/abbi.1995.1171
DO - 10.1006/abbi.1995.1171
M3 - 学術論文
C2 - 7893146
AN - SCOPUS:0028912204
SN - 0003-9861
VL - 317
SP - 331
EP - 336
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 2
ER -