[Analysis on the relationship between p57 and cholesterol in cellular membrane].
OBJECTIVE
To investigate the relationship between p57 and cholesterol in cellular membrane under physiological conditions.


METHODS
Different concentrations of mbetaCD were used to extract cholesterol from cellular membrane of U937 cells. The cellular membrane was prepared by ultracentrifugation and the content change of p57 in cellular membrane component was measured by Western blot analysis. Discontinuous sucrose density gradient centrifugation was used to prepare lipid rafts and the content of p57 in them was measured by Western blot analysis.


RESULTS
The degradation of cholesterol level in cellular membrane didn't lead to obvious content change of p57 in cellular membrane component. Furthermore, no p57 protein was found in lipid rafts.


CONCLUSIONS
No relationship between p57 and cholesterol in cellular membrane was found in the physiological condition, which is obviously different from that in pathological condition caused by the invasion of pathogenic mycobacteria.
Jin
Meng-meng
MM
Department of Endocrinology, Peking University First Hospital, Beijing 100034, China.
Zhang
Xiang
X
Hung
Peng
P
Zhang
Shi-qian
SQ
Zhang
Li-cheng
LC
Tang
Pei-fu
PF
D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D002784:Cholesterol / Q000032:analysis / Q000378:metabolism*; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D020298:U937 Cells
C493964:CDKN1C protein, human; D050761:Cyclin-Dependent Kinase Inhibitor p57; D002784:Cholesterol