TY - JOUR
T1 - Hypergravity signal transduction in HeLa cells with concomitant phosphorylation of proteins immunoprecipitated with anti-microtubule-associated protein antibodies
AU - Kumei, Yasuhiro
AU - Whitson, Peggy A.
AU - Sato, Atsushige
AU - Cintrón, Nitza M.
PY - 1991/2
Y1 - 1991/2
N2 - We have shown that hypergravity (35g) stimulates production of inositol 1,4,5-trisphosphate (IP3) and decreases adenosine 3′,5′-cyclic monophosphate (cAMP) levels in HeLa cells. IP3 production rapidly increased 1.5- and 2.1-fold greater (P < 0.05) than the control after 2- and 5-min exposures to 35g, respectively. The intracellular cAMP levels, determined in the presence of isobutylmethylxanthine, were decreased by 11% (P < 0.05) and 16% (P < 0.01) relative to the control after 10- and 20-min exposures to 35g, respectively. The phosphorylation of proteins which were immunoprecipitated by antibodies recognizing microtubule-associated proteins (ipMAPs) was also apparent after exposure of these cells to hypergravity. In the detergent-insoluble fraction, phosphorylation of a 115-kDa protein was significantly enhanced compared to the control after a 5-min exposure to 35g. In the detergent-soluble fraction, phosphorylation of a 200-kDa protein was observed after a 20-min exposure to 35g. Our study suggests that IP3 and cAMP may act as second messengers in hypergravity signal transduction. Phosphorylation of ipMAPs in both the detergent-soluble and -insoluble fractions suggests that cytoskeletal structures may be influenced by gravity.
AB - We have shown that hypergravity (35g) stimulates production of inositol 1,4,5-trisphosphate (IP3) and decreases adenosine 3′,5′-cyclic monophosphate (cAMP) levels in HeLa cells. IP3 production rapidly increased 1.5- and 2.1-fold greater (P < 0.05) than the control after 2- and 5-min exposures to 35g, respectively. The intracellular cAMP levels, determined in the presence of isobutylmethylxanthine, were decreased by 11% (P < 0.05) and 16% (P < 0.01) relative to the control after 10- and 20-min exposures to 35g, respectively. The phosphorylation of proteins which were immunoprecipitated by antibodies recognizing microtubule-associated proteins (ipMAPs) was also apparent after exposure of these cells to hypergravity. In the detergent-insoluble fraction, phosphorylation of a 115-kDa protein was significantly enhanced compared to the control after a 5-min exposure to 35g. In the detergent-soluble fraction, phosphorylation of a 200-kDa protein was observed after a 20-min exposure to 35g. Our study suggests that IP3 and cAMP may act as second messengers in hypergravity signal transduction. Phosphorylation of ipMAPs in both the detergent-soluble and -insoluble fractions suggests that cytoskeletal structures may be influenced by gravity.
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U2 - 10.1016/0014-4827(91)90068-6
DO - 10.1016/0014-4827(91)90068-6
M3 - Article
C2 - 1703085
AN - SCOPUS:0026073807
SN - 0014-4827
VL - 192
SP - 492
EP - 496
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -