Isolation of a mutant of Chinese hamster ovary cells with defective secretion of a subset of secretory proteins.
The secretory pathway of mammalian cells involves a complex sequence of steps beginning with the translation and translocation of proteins across the rough endoplasmic reticulum membrane followed by their transport through a variety of intracellular compartments. Understanding the cellular mechanisms involved in protein transport would be facilitated by the application of somatic cell genetics techniques. Therefore, we have developed a procedure for the isolation of Chinese hamster ovary cell lines that are deficient in this pathway. Mutant (sec) clones that secrete into the medium a lesser amount of newly synthesized protein relative to wild type are detected in the screen. One of the sec cell lines, LEH6, has similar growth and protein synthetic rates as do wild-type cells. The extent of total protein secretion is 60-70% of wild-type with some proteins more reduced than others. Immunoprecipitation studies indicate that for LEH6 cells there is impaired secretion of fibronectin (three- to fourfold) and major excreted protein (two- to sixfold).
Kaiden
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Department of Biochemistry, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205.
Krag
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D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003513:Cycloheximide / Q000494:pharmacology; D005353:Fibronectins / Q000378:metabolism; D066298:In Vitro Techniques; D008358:Mannose / Q000378:metabolism; D008970:Molecular Weight; D009154:Mutation; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D012636:Secretory Rate; D013696:Temperature
D005353:Fibronectins; D011506:Proteins; D003513:Cycloheximide; D008358:Mannose