Cyclic AMP-dependent phosphorylation of the precursor to beta subunit of mitochondrial F1-ATPase: a physiological mistake?
نویسنده
چکیده
By using the purified rat liver protein for reference in electrophoresis and peptide mapping experiments, I have identified the beta subunit of mitochondrial F1-ATPase and its cytoplasmic precursor in two-dimensional gel patterns of proteins from S49 mouse lymphoma cells. The beta subunit precursor is a substrate for cAMP-dependent phosphorylation during its synthesis. Normally, both nonphosphorylated and phosphorylated forms of beta subunit precursor are processed rapidly to the smaller, more acidic forms of mature beta subunit. When processing is inhibited with valinomycin, both nonphosphorylated and phosphorylated forms of beta subunit precursor are stabilized. Nonphosphorylated beta subunit is one of the most stable of cellular proteins, but the phosphorylated form is eliminated within minutes of processing. This suggests that phosphorylated beta subunit is recognized as aberrant and excluded from assembly into the ATPase complex. These results argue that cAMP-dependent phosphorylation of the beta subunit precursor is a physiological mistake that is remedied after mitochondrial import and processing.
منابع مشابه
Cyclic AMP-dependent Phosphorylation of the Precursor to # Subunit of Mitochondrial F
By using the purified rat liver protein for reference in electrophoresis and peptide mapping experiments, I have identified the a subunit of mitochondrial F 1 -ATPase and its cytoplasmic precursor in two-dimensional gel patterns of proteins from S49 mouse lymphoma cells . The a subunit precursor is a substrate for cAMP-dependent phosphorylation during its synthesis . Normally, both nonphosphory...
متن کاملSynthesis of mitochondrial uncoupling protein in brown adipocytes differentiated in cell culture.
In order to characterize the biogenesis of unique thermogenic mitochondria of brown adipose tissue, differentiation of precursor cells isolated from mouse brown adipose tissue was studied in cell culture. Synthesis of mitochondrial uncoupling protein (UCP), F1-ATPase, and cytochrome oxidase was examined by L-[35S]methionine labeling and immunoblotting. For the first time, synthesis of physiolog...
متن کاملPrecursor proteins are transported into mitochondria in the absence of proteolytic cleavage of the additional sequences.
Many nuclear-coded mitochondrial proteins are synthesized as larger precursor polypeptides that are proteolytically processed during import into the mitochondrion. This processing appears to be catalyzed by a soluble, metal-dependent protease localized in the mitochondrial matrix. In this report we employ an in vitro system to investigate the role of processing in protein import. Intact Neurosp...
متن کاملThe yeast F1-ATPase beta subunit precursor contains functionally redundant mitochondrial protein import information.
The NH2 terminus of the yeast F1-ATPase beta subunit precursor directs the import of this protein into mitochondria. To define the functionally important components of this import signal, oligonucleotide-directed mutagenesis was used to introduce a series of deletion and missense mutations into the gene encoding the F1-beta subunit precursor. Among these mutations were three nonoverlapping dele...
متن کاملmRNA encoding the beta-subunit of the mitochondrial F1-ATPase complex is a localized mRNA in rat hepatocytes.
Subcellular mRNA localization has emerged as a mechanism for regulation of gene expression and protein-sorting pathways. Here we describe the different cytoplasmic presentation in rat hepatocytes of two nuclear mRNA species encoding subunits alpha and beta of the mitochondrial F1-ATPase complex. alpha-F1-ATPase mRNA is dispersed and scattered in the cytoplasm. In contrast, beta-F1-ATPase mRNA a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of Cell Biology
دوره 98 شماره
صفحات -
تاریخ انتشار 1984