Studies of Membrane Formation in Tetrahymena pyriformis

摘要: Abstract An experimental system has been developed to analyze the synthesis and intracellular deployment of proteins in growing cells Tetrahymena pyriformis. There are marked differences rates at which radioactive appear various parts cell, including certain membranes, following [3H]leucine pulse-chase labeling experiments. Proteins labeled during a 5-min exposure isotope require approximately 2 hours for dissemination. Polyacrylamide gel electrophoresis indicated that all individual particular cell fraction accumulate radioactivity equivalent rates, except case cilia. Further subfractionation purified cilia yielded three components: matrix, axonemes, membranes. The latter was found have relatively simple protein composition involving only four major constituents. matrix fraction, had highest specific immediately 3H pulse, appeared contain new being conveyed membranes axonemes. By chase, subfractions nearly radioactivities. Radioactive membrane lipids also seem be transported into via fraction. However, ciliary more slowly than do proteins, apparently because tendency exchange with pre-existing lipid molecules encountered first stages transport. Other qualify as potentially rewarding model studying process assembly.