Vascular Patterning Laboratory, Center for Cancer Biology, VIB, Leuven, Belgium; Vascular Patterning Laboratory, Center for Cancer Biology, Department of Oncology, VIB, Leuven, Belgium
Pavel Nedvetsky
Vascular Patterning Laboratory, Center for Cancer Biology, VIB, Leuven, Belgium; Vascular Patterning Laboratory, Center for Cancer Biology, Department of Oncology, VIB, Leuven, Belgium; Medical Cell Biology, Medical Clinic D, University Hospital Münster, Münster, Germany
Fabio Stanchi
Vascular Patterning Laboratory, Center for Cancer Biology, VIB, Leuven, Belgium; Vascular Patterning Laboratory, Center for Cancer Biology, Department of Oncology, VIB, Leuven, Belgium
Integrative Vascular Biology Lab, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany; INSERM UMR-970, Paris Cardiovascular Research Center, Paris Descartes University, Paris, France
Oliver Popp
Proteomics, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
Kerstin Zühlke
Anchored Signaling Lab, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
Gunnar Dittmar
Proteomics, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany; CRP Santé · Department of Oncology, LIH Luxembourg Institute of Health, Luxembourg, Luxembourg
Anchored Signaling Lab, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany; DZHK (German Center for Cardiovascular Research), Berlin, Germany
Vascular Patterning Laboratory, Center for Cancer Biology, VIB, Leuven, Belgium; Vascular Patterning Laboratory, Center for Cancer Biology, Department of Oncology, VIB, Leuven, Belgium; Integrative Vascular Biology Lab, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany; DZHK (German Center for Cardiovascular Research), Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany
The cAMP-dependent protein kinase A (PKA) regulates various cellular functions in health and disease. In endothelial cells PKA activity promotes vessel maturation and limits tip cell formation. Here, we used a chemical genetic screen to identify endothelial-specific direct substrates of PKA in human umbilical vein endothelial cells (HUVEC) that may mediate these effects. Amongst several candidates, we identified ATG16L1, a regulator of autophagy, as novel target of PKA. Biochemical validation, mass spectrometry and peptide spot arrays revealed that PKA phosphorylates ATG16L1α at Ser268 and ATG16L1β at Ser269, driving phosphorylation-dependent degradation of ATG16L1 protein. Reducing PKA activity increased ATG16L1 protein levels and endothelial autophagy. Mouse in vivo genetics and pharmacological experiments demonstrated that autophagy inhibition partially rescues vascular hypersprouting caused by PKA deficiency. Together these results indicate that endothelial PKA activity mediates a critical switch from active sprouting to quiescence in part through phosphorylation of ATG16L1, which in turn reduces endothelial autophagy.
