| First Author | Ilouz R | Year | 2012 |
| Journal | Proc Natl Acad Sci U S A | Volume | 109 |
| Issue | 31 | Pages | 12443-8 |
| PubMed ID | 22797896 | Mgi Jnum | J:188520 |
| Mgi Id | MGI:5440803 | Doi | 10.1073/pnas.1209538109 |
| Citation | Ilouz R, et al. (2012) Localization and quaternary structure of the PKA RIbeta holoenzyme. Proc Natl Acad Sci U S A 109(31):12443-8 |
| abstractText | Specificity for signaling by cAMP-dependent protein kinase (PKA) is achieved by both targeting and isoform diversity. The inactive PKA holoenzyme has two catalytic (C) subunits and a regulatory (R) subunit dimer (R(2):C(2)). Although the RIalpha, RIIalpha, and RIIbeta isoforms are well studied, little is known about RIbeta. We show here that RIbeta is enriched selectively in mitochondria and hypothesized that its unique biological importance and functional nonredundancy will correlate with its structure. Small-angle X-ray scattering showed that the overall shape of RIbeta(2):C(2) is different from its closest homolog, RIalpha(2):C(2). The full-length RIbeta(2):C(2) crystal structure allows us to visualize all the domains of the PKA holoenzyme complex and shows how isoform-specific assembly of holoenzyme complexes can create distinct quaternary structures even though the R(1):C(1) heterodimers are similar in all isoforms. The creation of discrete isoform-specific PKA holoenzyme signaling "foci" paves the way for exploring further biological roles of PKA RIbeta and establishes a paradigm for PKA signaling. |
