Catalytic subunit of cyclic AMP-dependent protein kinase

Where it participates (unsigned role)

1. Prior incubation of recombinant phosphodiesterase type 5 with protein kinase G, magnesium ATP and cyclic GMP, producing serine 92 phosphorylation, caused a 50 to 70% increase in enzyme activity and increased the affinity of cyclic GMP binding to the allosteric sites, reducing the concentration needed for half-maximum allosteric binding from 0.13 to 0.03 micromolar, with stimulation obtained at 0.2 to 0.5 micromolar kinase subunit which is approximately the cellular level in vascular smooth muscle, while considerably higher concentrations of protein kinase A were required.

   cGMP-dependent protein kinase I → Phosphodiesterase 5 family source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/sildenafil-research/10785399.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d4048089a01ed860c8a71d096eb5bf1407e19557ca97c88b6cbac0e5f69de171", "start_char": 0, "end_char": 2100, "text_sha256": "d4048089a01ed860c8a71d096eb5bf1407e19557ca97c88b6cbac0e5f69de171"}

   experimental_model

   Phosphorylation of recombinant bovine phosphodiesterase type 5 at serine 92 with activity and binding measurement

   exposure

   Protein kinase G or the catalytic subunit of protein kinase A with magnesium ATP and cyclic GMP

   limitations

   Establishes the feedback loop and shows the kinase concentrations are physiological. It also records that phosphorylation does not change the potency of the drug, which matters for whether the loop blunts the drug.

   nutrient_topic

   Sildenafil research collection; topical membership is not evidence of a direct clinical effect, and the drug is recorded separately from its N-desmethyl metabolite and its target enzyme from the homologous retinal PDE6. · Sildenafil

   organism

   Cattle enzyme

   plain_language

   The messenger switches on a kinase that speeds up the enzyme destroying it, which is a brake the cell applies to itself.

   primary_references

   [sil-p10785399] Phosphorylation of phosphodiesterase-5 by cyclic nucleotide-dependent protein kinase alters its catalytic and allosteric cGMP-binding activities. (2000). https://pubmed.ncbi.nlm.nih.gov/10785399/ DOI: 10.1046/j.1432-1327.2000.01297.x

   tissue_or_cell_type

   Recombinant enzyme and lung extract

   Sildenafil: the enzyme it occupies instead of the substrate, why it cannot start a signal it can only preserve, the organic nitrate interaction that follows from that, the homologous retinal enzyme ten-fold away, and the pulmonary circulation where the same mechanism became a second indication (2026-09-22) · lines 197–208

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Phosphorylation of recombinant bovine phosphodiesterase type 5 at serine 92 with activity and binding measurement · source_derived_draft · unverified_draft

   ### sil-pkg-feedback-speeds-the-enzyme Prior incubation of recombinant phosphodiesterase type 5 with protein kinase G, magnesium ATP and cyclic GMP, producing serine 92 phosphorylation, caused a 50 to 70% increase in enzyme activity and increased the affinity of cyclic GMP binding to the allosteric sites, reducing the concentration needed for half-maximum allosteric binding from 0.13 to 0.03 micromolar, with stimulation obtained at 0.2 to 0.5 micromolar kinase subunit which is approximately the cellular level in vascular smooth muscle, while considerably higher concentrations of protein kinase A were required. Condition category: normal nutrient_topic: Sildenafil research collection; topical membership is not evidence of a direct clinical effect, and the drug is recorded separately from its N-desmethyl metabolite and its target enzyme from the homologous retinal PDE6. plain_language: The messenger switches on a kinase that speeds up the enzyme destroying it, which is a brake the cell applies to itself. organism: Cattle enzyme tissue_or_cell_type: Recombinant enzyme and lung extract experimental_model: Phosphorylation of recombinant bovine phosphodiesterase type 5 at serine 92 with activity and binding measurement limitations: Establishes the feedback loop and shows the kinase concentrations are physiological. It also records that phosphorylation does not change the potency of the drug, which matters for whether the loop blunts the drug. exposure: Protein kinase G or the catalytic subunit of protein kinase A with magnesium ATP and cyclic GMP evidence_span: {"source_cache": "artifacts/sildenafil-research/10785399.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d4048089a01ed860c8a71d096eb5bf1407e19557ca97c88b6cbac0e5f69de171", "start_char": 0, "end_char": 2100, "text_sha256": "d4048089a01ed860c8a71d096eb5bf1407e19557ca97c88b6cbac0e5f69de171"} [sil-p10785399] Phosphorylation of phosphodiesterase-5 by cyclic nucleotide-dependent protein kinase alters its catalytic and allosteric cGMP-binding activities. (2000). https://pubmed.ncbi.nlm.nih.gov/10785399/ DOI: 10.1046/j.1432-1327.2000.01297.x

   Complete structured claim and evidence