Skip to main content
Article thumbnail
Location of Repository

Neurospora crassa cytoplasmic ribosomes: cold-sensitive mutant defective in ribosomal ribonucleic acid synthesis.

By P J Russell, J R Hammett and E U Selker


Experiments were conducted to characterize further the biochemical defects of crib-1 (PJ30201), a coldsensitive mutant strain of Neurospora crassa with a defect in ribosome biosynthesis. The results are as follows. (i) The critical temperature for the expression of the mutant growth and ribosome phenotypes is in the range of 18 to 20 C. (ii) No preferential breakdown of 37S cytoplasmic ribosomal subunits synthesized by crib-1 at 25 C occurs after a shift to 10 C. (iii) Ribosomal subunits synthesized by crib-1 at 25 C function normally in in vivo protein synthesis at 10 C. (iv) Whereas wild type synthesizes both ribosomal subunits in a coordinate manner after either a temperature shift-down (25 to 10 C) of a shift-up (10 to 25 C), noncoordinate synthesis of ribosomal subunits owing to underproduction of 37S subunits occurs in the crib-1 strain immediately after a temperature shift-down. (v) After a shift from 10 to 25 C crib-1 exhibits a 12-h lag before the growth rate and the rate of synthesis of 37S subunits begin to increase significantly. (vi) At 10 C crib-1 synthesizes unequal amounts of 25S and 17S ribosomal ribonucleic acid (rRNA) molecules, resulting from a greatly reduced accumulation of stable 17S rRNA. The mutant phenotypes of crib-1 are proposed to be the result of a defect in rRNA processing

Topics: Research Article
Year: 1976
OAI identifier:
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.