| Autor: |
Richard E. Cutler, Andrew R. Labarbera, Deborah A. DeManno, Marilyn L. G. Lamm, B. D. Sanwal, Mary Hunzicker-Dunn, J Erlichman, Evelyn T. Maizels |
| Rok vydání: |
1991 |
| Předmět: |
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| Zdroj: |
Journal of Biological Chemistry. 266:7166-7175 |
| ISSN: |
0021-9258 |
| DOI: |
10.1016/s0021-9258(20)89625-2 |
| Popis: |
Regulatory (R) subunits and their association with catalytic subunits to form cAMP-dependent protein kinase holoenzymes were investigated in corpora lutea of pregnant rats. Following separation by DEAE-cellulose chromatography, R subunits were identified by labeling with 8-N3[32P]cAMP and autophosphorylation on one and two-dimensional gel electrophoresis and by reactivity with antisera. DEAE-cellulose elution of R subunits with catalytic subunits as holoenzymes or without catalytic subunits was determined by sedimentation characteristics on sucrose density gradient centrifugation and by cAMP-stimulated kinase activation characteristics on Eadie-Scatchard analysis. We identified the presence of a type I holoenzyme containing RI alpha (Mr 47,000) subunits, a prominent type II holoenzyme containing RII beta (Mr 52,000) subunits, and a second more acidic type II holoenzyme peak containing both RII beta and RII alpha (Mr 54,000) subunits. However, the majority of total R subunit activity was associated with a catalytic subunit-free peak of RI alpha protein which on elution from DEAE-cellulose was associated with cAMP. This report establishes the more basic elution position from DEAE-cellulose of the prominent rat luteal RII beta holoenzyme in very close proximity to free RI alpha and presents one of the few reports of a normal tissue containing a large percentage of catalytic subunit-free RI alpha. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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