Characterization of two mutants of the LLC-PK1 porcine kidney cell line affected in the catalytic subunit of the cAMP-dependent protein kinase.

摘要: The catalytic (C) subunit activity of the cAMP-dependent protein kinase (cAMP-PK) from mutant cell lines, FIB4 and FIB6, is only 10% compared with parent line, LLC-PK1 [Jans Hemmings (1986) FEBS Lett. 205, 127–131]. In order to understand nature phenotypes cAMP-PK lines was studied in more detail. Analysis by ion-exchange chromatography revealed that associated type I holoenzyme both FIB6 5% parental, II about 20% parental. regulatory (RI) subunits were also found be reduced 70–80% mutants, whereas R levels similar parent. residual could not activated cAMP (Ka 5.5 × 10−8M), showed normal affinities for Kemptamide ATP. A polyclonal antibody used quantify level this wild-type cells. This analysis had nearly C subunit, suggesting synthesized mutants mostly inactive. As holoenzymes abnormal, most likely explanation phenotype a defect either structural gene or an enzyme involved its posttranslational processing. However, second lesion affecting RI cannot ruled out at moment.