![Fig. 9. Effects of MPSD and Ala-MPSD on the phosphorylation of pleckstrin (p47) and myosin light chain (p20) induced by PKC activation. / (A) An experiment similar to that described in the legend to Figure 8was performed on [32P]PI–labeled platelets except that, here, total platelet extracts (heat-stable plus heat-sensitive proteins) were prepared. SDS-PAGE, electrotransfers, autoradiography, scanning, and integration of peak areas (arbitrary units) were performed as indicated in the legend to Figure 8 and in “Materials and methods.” The arrow and the arrowhead indicate the position of pleckstrin and myosin light chain (MLC), respectively. The asterisk shows the position of phosphorylated MPSD, which in this gel system migrated with another unknown phosphoprotein present in all lines. Pleckstrin and MLC phosphorylations were not modified by either MPSD or Ala-MPSD. (B) Cumulative data on protein phosphorylation obtained from experiments carried out on different platelet preparations are shown. Experiments were performed as described above in A for pleckstrin and MLC and as indicated in legend to Figure 8 for MARCKS. Bars represent mean ± SEM of [32P]Pi incorporation, expressed as a percentage of control (absence of PMA), obtained from 3 to 4 different experiments for each condition tested.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/95/3/10.1182_blood.v95.3.894.003k15_894_902/6/bloo00315009w.jpeg?Expires=1724239624&Signature=N4MtlXeNe7KtRAeIU-L1cTlwRwmXSnmWp9Tiya58jslhet1WyBGOerf5Ox3kmFGVKS8YcaMAfnNZO6XwEUxm027jm03ti1YkYjTmJTaQ6o07GWGziuC6JcBNfoN8qm7h6Jt6fuR7lMRjngHPEf2Rev-Ztx2u8vMELFiQQngONALyX2tPYFctvfMyz2V3tKgo9quXDKJXnJKmcZ06ZYh4pKx~0zzg5jLSspOTp08XuvumUPYkfCoEtHpq~FeimqsSApi8XH2iLpG5pfpoW4YKSr8XZRFKv7O5IOC47apWVHu~2Xv6YWrMV~rLbDycVtnSl2c3F297Ni-d9YT2wGLjuA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Effects of MPSD and Ala-MPSD on the phosphorylation of pleckstrin (p47) and myosin light chain (p20) induced by PKC activation.
(A) An experiment similar to that described in the legend to Figure 8was performed on [32P]PI–labeled platelets except that, here, total platelet extracts (heat-stable plus heat-sensitive proteins) were prepared. SDS-PAGE, electrotransfers, autoradiography, scanning, and integration of peak areas (arbitrary units) were performed as indicated in the legend to Figure 8 and in “Materials and methods.” The arrow and the arrowhead indicate the position of pleckstrin and myosin light chain (MLC), respectively. The asterisk shows the position of phosphorylated MPSD, which in this gel system migrated with another unknown phosphoprotein present in all lines. Pleckstrin and MLC phosphorylations were not modified by either MPSD or Ala-MPSD. (B) Cumulative data on protein phosphorylation obtained from experiments carried out on different platelet preparations are shown. Experiments were performed as described above in A for pleckstrin and MLC and as indicated in legend to Figure 8 for MARCKS. Bars represent mean ± SEM of [32P]Pi incorporation, expressed as a percentage of control (absence of PMA), obtained from 3 to 4 different experiments for each condition tested.
