Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1994-3-4
pubmed:abstractText
The catalytic (C) subunit of cAMP-dependent protein kinase is inhibited by the regulatory (R) subunit and by a thermostable inhibitor (PKI). Both inhibitors also affect the intracellular distribution of the C subunit. Whether injected into the cytoplasm or into the nucleus, free C subunit can enter and exit the nucleus freely. After 30 min its distribution is identical and is independent of the initial site of injection. In contrast, when C is injected into the cytoplasm complexed with R or PKI, the complexes are restricted to the cytoplasm (1-3). However, unlike the R subunit, which is restricted to the cytoplasm like the holoenzyme, free PKI enters the nucleus rapidly following its injection into the cytoplasm. When holoenzyme is injected directly into the nucleus, it cannot exit and return to the cytoplasm. In contrast, nuclear injection of a C.PKI complex results in the rapid exit of the C subunit from the nucleus. In equilibrated cells previously injected with the C subunit, subsequent cytoplasmic injection of either PKI or type 1 R depletes the nucleus of C although PKI does so faster, consistent with its ability to enter the nucleus. Both inhibitors block the cAMP response element-regulated gene expression. Hence PKI may serve as a nuclear scavenger of C providing a mechanism not only for inhibition but also for subcellular localization in the presence of cAMP by restricting the access of the C subunit to the nucleus.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2676-86
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8300597-Animals, pubmed-meshheading:8300597-Carrier Proteins, pubmed-meshheading:8300597-Cell Line, pubmed-meshheading:8300597-Cell Nucleus, pubmed-meshheading:8300597-Cyclic AMP, pubmed-meshheading:8300597-Cyclic AMP-Dependent Protein Kinases, pubmed-meshheading:8300597-Cytoplasm, pubmed-meshheading:8300597-Enzyme Stability, pubmed-meshheading:8300597-Gene Expression Regulation, Enzymologic, pubmed-meshheading:8300597-Hot Temperature, pubmed-meshheading:8300597-Immunoglobulin G, pubmed-meshheading:8300597-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:8300597-Kinetics, pubmed-meshheading:8300597-Macromolecular Substances, pubmed-meshheading:8300597-Rabbits, pubmed-meshheading:8300597-Recombinant Proteins, pubmed-meshheading:8300597-Spectrometry, Fluorescence, pubmed-meshheading:8300597-Thermodynamics, pubmed-meshheading:8300597-Time Factors
pubmed:year
1994
pubmed:articleTitle
Thermostable inhibitor of cAMP-dependent protein kinase enhances the rate of export of the kinase catalytic subunit from the nucleus.
pubmed:affiliation
Department of Chemistry, University of California, San Diego, La Jolla 92093-0613.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't