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Bock A, Irannejad R, Scott JD. cAMP signaling: a remarkably regional affair. Trends Biochem Sci 2024; 49:305-317. [PMID: 38310024 PMCID: PMC11175624 DOI: 10.1016/j.tibs.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/22/2023] [Accepted: 01/10/2024] [Indexed: 02/05/2024]
Abstract
Louis Pasteur once famously said 'in the fields of observation chance favors only the prepared mind'. Much of chance is being in the right place at the right time. This is particularly true in the crowded molecular environment of the cell where being in the right place is often more important than timing. Although Brownian motion argues that enzymes will eventually bump into substrates, this probability is greatly enhanced if both molecules reside in the same subcellular compartment. However, activation of cell signaling enzymes often requires the transmission of chemical signals from extracellular stimuli to intracellular sites of action. This review highlights new developments in our understanding of cAMP generation and the 3D utilization of this second messenger inside cells.
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Affiliation(s)
- Andreas Bock
- Rudolf Boehm Institute of Pharmacology and Toxicology, Medical Faculty, Leipzig University, 04107 Leipzig, Germany.
| | - Roshanak Irannejad
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - John D Scott
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA.
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Lauer SM, Omar MH, Golkowski MG, Kenerson HL, Lee KS, Pascual BC, Lim HC, Forbush K, Smith FD, Gordan JD, Ong SE, Yeung RS, Scott JD. Recruitment of BAG2 to DNAJ-PKAc scaffolds promotes cell survival and resistance to drug-induced apoptosis in fibrolamellar carcinoma. Cell Rep 2024; 43:113678. [PMID: 38236773 PMCID: PMC10964278 DOI: 10.1016/j.celrep.2024.113678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/23/2023] [Accepted: 01/02/2024] [Indexed: 01/30/2024] Open
Abstract
The DNAJ-PKAc fusion kinase is a defining feature of fibrolamellar carcinoma (FLC). FLC tumors are notoriously resistant to standard chemotherapies, with aberrant kinase activity assumed to be a contributing factor. By combining proximity proteomics, biochemical analyses, and live-cell photoactivation microscopy, we demonstrate that DNAJ-PKAc is not constrained by A-kinase anchoring proteins. Consequently, the fusion kinase phosphorylates a unique array of substrates, including proteins involved in translation and the anti-apoptotic factor Bcl-2-associated athanogene 2 (BAG2), a co-chaperone recruited to the fusion kinase through association with Hsp70. Tissue samples from patients with FLC exhibit increased levels of BAG2 in primary and metastatic tumors. Furthermore, drug studies implicate the DNAJ-PKAc/Hsp70/BAG2 axis in potentiating chemotherapeutic resistance. We find that the Bcl-2 inhibitor navitoclax enhances sensitivity to etoposide-induced apoptosis in cells expressing DNAJ-PKAc. Thus, our work indicates BAG2 as a marker for advanced FLC and a chemotherapeutic resistance factor in DNAJ-PKAc signaling scaffolds.
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Affiliation(s)
- Sophia M Lauer
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Mitchell H Omar
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Martin G Golkowski
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Heidi L Kenerson
- Department of Surgery, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Kyung-Soon Lee
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Bryan C Pascual
- Division of Hematology and Oncology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Huat C Lim
- Division of Hematology and Oncology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Katherine Forbush
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - F Donelson Smith
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - John D Gordan
- Division of Hematology and Oncology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Shao-En Ong
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Raymond S Yeung
- Department of Surgery, University of Washington Medical Center, Seattle, WA 98195, USA
| | - John D Scott
- Department of Pharmacology, University of Washington Medical Center, Seattle, WA 98195, USA.
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Reggi E, Kaiser S, Sahnane N, Uccella S, La Rosa S, Diviani D. AKAP2-anchored protein phosphatase 1 controls prostatic neuroendocrine carcinoma cell migration and invasion. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166916. [PMID: 37827203 DOI: 10.1016/j.bbadis.2023.166916] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/20/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023]
Abstract
Prostate cancer (PC) is the second leading cause of cancer-related death in men. The growth of primary prostate cancer cells relies on circulating androgens and thus the standard therapy for the treatment of localized and advanced PC is the androgen deprivation therapy. Prostatic neuroendocrine carcinoma (PNEC) is an aggressive and highly metastatic subtype of prostate cancer, which displays poor prognosis and high lethality. Most of PNECs develop from prostate adenocarcinoma in response to androgen deprivation therapy, however the mechanisms involved in this transition and in the elevated biological aggressiveness of PNECs are poorly defined. Our current findings indicate that AKAP2 expression is dramatically upregulated in PNECs as compared to non-cancerous prostate tissues. Using a PNEC cell model, we could show that AKAP2 is localized both intracellularly and at the cell periphery where it colocalizes with F-actin. AKAP2 and F-actin interact directly through a newly identified actin-binding domain located on AKAP2. RNAi-mediated silencing of AKAP2 promotes the phosphorylation and deactivation of cofilin, a protein involved in actin turnover. This effect correlates with a significant reduction in cell migration and invasion. Co-immunoprecipitation experiments and proximity ligation assays revealed that AKAP2 forms a complex with the catalytic subunit of protein phosphatase 1 (PP1) in PNECs. Importantly, AKAP2-mediated anchoring of PP1 to the actin cytoskeleton regulates cofilin dephosphorylation and activation, which, in turn, enhances F-actin dynamics and favors migration and invasion. In conclusion, this study identified AKAP2 as an anchoring protein overexpressed in PNECs that controls cancer cell invasive properties by regulating cofilin phosphorylation.
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Affiliation(s)
- Erica Reggi
- Department of Biomedical Sciences, Faculty of Biology et Medicine, University of Lausanne, 1011 Lausanne, Switzerland
| | - Simon Kaiser
- Department of Biomedical Sciences, Faculty of Biology et Medicine, University of Lausanne, 1011 Lausanne, Switzerland
| | - Nora Sahnane
- Unit of Pathology, Department of Oncology, ASST Sette Laghi, Varese, Italy
| | - Silvia Uccella
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Pathology Service, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Humanitas Research Hospital, Milan, Italy
| | - Stefano La Rosa
- Unit of Pathology, Department of Oncology, ASST Sette Laghi, Varese, Italy; Unit of Pathology, Department of Medicine and Technological Innovation, University of Insubria, Varese, Italy
| | - Dario Diviani
- Department of Biomedical Sciences, Faculty of Biology et Medicine, University of Lausanne, 1011 Lausanne, Switzerland.
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Lauer SM, Omar MH, Golkowski MG, Kenerson HL, Pascual BC, Forbush K, Smith FD, Gordan J, Ong SE, Yeung RS, Scott JD. Recruitment of BAG2 to DNAJ-PKAc scaffolds promotes cell survival and resistance to drug-induced apoptosis in fibrolamellar carcinoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.28.546958. [PMID: 37425703 PMCID: PMC10327129 DOI: 10.1101/2023.06.28.546958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The DNAJ-PKAc fusion kinase is a defining feature of the adolescent liver cancer fibrolamellar carcinoma (FLC). A single lesion on chromosome 19 generates this mutant kinase by creating a fused gene encoding the chaperonin binding domain of Hsp40 (DNAJ) in frame with the catalytic core of protein kinase A (PKAc). FLC tumors are notoriously resistant to standard chemotherapies. Aberrant kinase activity is assumed to be a contributing factor. Yet recruitment of binding partners, such as the chaperone Hsp70, implies that the scaffolding function of DNAJ- PKAc may also underlie pathogenesis. By combining proximity proteomics with biochemical analyses and photoactivation live-cell imaging we demonstrate that DNAJ-PKAc is not constrained by A-kinase anchoring proteins. Consequently, the fusion kinase phosphorylates a unique array of substrates. One validated DNAJ-PKAc target is the Bcl-2 associated athanogene 2 (BAG2), a co-chaperone recruited to the fusion kinase through association with Hsp70. Immunoblot and immunohistochemical analyses of FLC patient samples correlate increased levels of BAG2 with advanced disease and metastatic recurrences. BAG2 is linked to Bcl-2, an anti-apoptotic factor that delays cell death. Pharmacological approaches tested if the DNAJ- PKAc/Hsp70/BAG2 axis contributes to chemotherapeutic resistance in AML12 DNAJ-PKAc hepatocyte cell lines using the DNA damaging agent etoposide and the Bcl-2 inhibitor navitoclax. Wildtype AML12 cells were susceptible to each drug alone and in combination. In contrast, AML12 DNAJ-PKAc cells were moderately affected by etoposide, resistant to navitoclax, but markedly susceptible to the drug combination. These studies implicate BAG2 as a biomarker for advanced FLC and a chemotherapeutic resistance factor in DNAJ-PKAc signaling scaffolds.
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