Turnover and intranuclear localization of 125I-insulin in Tetrahymena. An autoradiographic study.
The unicellular Tetrahymena first internalized, then partly released the labelled insulin. Insulin-pretreated (imprinted) Tetrahymena cells behaved differently from non-pretreated cells, in that they retained a greater part of internalized insulin in the cytoplasm. Additional exposure to excessive non-labelled (cold) insulin caused a decrease in intracellular labelled insulin retention. Internalized insulin also entered the nucleus of Tetrahymena, where it was found in a heterochromatic localization.
Fülöp
A K
AK
Department of Biology, Semmelweis University of Medicine, Budapest, Hungary.
Csaba
G
G
D000818:Animals; D001345:Autoradiography; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000737:chemistry; D007328:Insulin / Q000032:analysis / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008854:Microscopy, Electron; D013769:Tetrahymena pyriformis / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure
D007328:Insulin; D007457:Iodine Radioisotopes