Role of Scd5, a protein phosphatase-1 targeting protein, in phosphoregulation of Sla1 during endocytosis.

Phosphorylation regulates assembly and disassembly of proteins during endocytosis. In yeast, Prk1 and Ark1 phosphorylate factors after vesicle internalization leading to coat disassembly. Scd5, a protein phosphatase-1 (PP1)-targeting subunit, is proposed to regulate dephosphorylation of Prk1/Ark1 substrates to promote new rounds of endocytosis.

Phosphatidylinositol synthase of Tetrahymena: inositol isomers as substrates in phosphatidylinositol biosynthesis and headgroup exchange reactions.

Phosphatidylinositol (PtdIns) synthase in microsomal fractions derived from Tetrahymena vorax was studied to determine its activity requirements. The suitability of inositol isomers as substrates for the synthase and in headgroup exchange reactions also was investigated. Tetrahymena PtdIn synthase activity was optimum in the presence of 2 mM MgCl2 plus 2 mM MnCl2, a pH of 7.

Reduction in blood platelet size with increase in circulating numbers in the postoperative period and a comparison of the glass bead and rotating bulb methods for detecting changes in function.

The changes in blood platelet numbers, size, adhesiveness, and response to adenosine diphosphate have been followed for about a month after major operations performed on 19 patients. The well established increase in numbers was confirmed and reached a maximum of rather less than double the normal numbers in the third week. It was accompanied by a reduction of platelet size from 8.