Expression of A kinase anchor protein 121 is regulated by hormones in thyroid and testicular germ cells

Antonio Feliciello, Charles S. Rubin, Enrico V. Awedimento, Max E. Gottesman

Research output: Contribution to journalArticlepeer-review

47 Scopus citations


Distinct A Kinase Anchor Proteins (AKAPs) immobilize and concentrate protein kinase A II (PKAII) isoforms at specific intracellular locations. AKAP121 binds and targets PKAIIα to the cytoplasmic surface of mitochondria. Mechanisms that control expression of this mitochondrial AKAP are unknown. We have cloned cDNA for rat AKAP121 and show that AKAP121 protein expression is regulated by thyroid stimulating hormone (TSH) and cAMP. Differentiated thyroid cells (TL5) accumulate AKAP121 upon incubation with TSH or a cAMP analog. Levels of total and newly synthesized AKAP121 mRNA also increased after treatment. AKAP121 mRNA accumulated in the presence of cycloheximide, suggesting that transcription of the anchor protein gene is directly controlled by cAMP and PKA. AKAP121 is induced with similar kinetics when an unrelated, spermatocyte-derived cell line (GC-2) is incubated with 8- chlorophenylthio-cAMP. Thus, AKAP121 concentration may be controlled by hormones that activate adenylate cyclase. This mode of regulation could provide a general mechanism for (a) enhancing the sensitivity of distal organelles to cAMP and (b) shifting the focus of cAMP-mediated signaling from cytoplasm to organelles.

Original languageEnglish (US)
Pages (from-to)23361-23366
Number of pages6
JournalJournal of Biological Chemistry
Issue number36
StatePublished - Sep 4 1998

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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