Receptor-specific contributions of caveolae, PKC, and Src tyrosine kinase to serotonergic and adrenergic regulation of Kv channels and vasoconstriction

• Published in: Life sciences (1973) Vol. 328; p. 121903
• Main Authors: Sung, Dong Jun, Park, Solah, Noh, Hyun Ju, Golpasandi, Shadi, Eun, Seo Hyeon, Lee, Hyeryeong, Kim, Bokyung, Wie, Jinhong, Seo, Mi Seon, Park, Sang Woong, Bae, Young Min
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.09.2023
• Subjects: 5-HT2A receptor; Adrenergic Agents - metabolism; Adrenergic Agents - pharmacology; Animals; Caveolae; Caveolae - metabolism; Protein Kinase C - metabolism; Protein Kinase Inhibitors - pharmacology; Protein kinase-C; Rats; Receptor, Serotonin, 5-HT2A - metabolism; Receptors, Adrenergic - metabolism; Serotonin - metabolism; Serotonin - pharmacology; Src tyrosine kinase; src-Family Kinases - metabolism; Vasoconstriction; Voltage-dependent K+ channels (Kv); α1-adrenoceptor; Voltage-dependent K+ channels (Kv); DMSO; NT; Kv; Src tyrosine kinase; DMEM; MβCD; FBS; Protein kinase-C; Caveolae; Vasoconstriction; PKC; DAG; IP3; 5-HT2AR; PLCβ; PSS; TEA; PP3; 5-HT2A receptor; PP2; NE; 5-HT; α1-adrenoceptor; ERK; 5-HT(2A) receptor; Voltage-dependent K(+) channels (Kv)
• DOI: 10.1016/j.lfs.2023.121903
• ISSN: 0024-3205; 1879-0631

Caveolae are invaginated, Ω-shaped membrane structures. They are now recognized as portals for signal transduction of multiple chemical and mechanical stimuli. Notably, the contribution of caveolae has been reported to be receptor-specific. However, details of how they differentially contribute to receptor signaling remain unclear. Using isometric tension measurements, patch-clamping, and western blotting, we examined the contribution of caveolae and their related signaling pathways to serotonergic (5-HT2A receptor-mediated) and adrenergic (α1-adrenoceptor-mediated) signaling in rat mesenteric arteries. Disruption of caveolae by methyl-β-cyclodextrin effectively blocked vasoconstriction mediated by the 5-HT2A receptor (5-HT2AR), but not by the α1-adrenoceptor. Caveolar disruption selectively impaired 5-HT2AR-mediated voltage-dependent K+ channel (Kv) inhibition, but not α1-adrenoceptor-mediated Kv inhibition. In contrast, both serotonergic and α1-adrenergic effects on vasoconstriction, as well as Kv currents, were similarly blocked by the Src tyrosine kinase inhibitor PP2. However, inhibition of protein kinase C (PKC) by either GO6976 or chelerythrine selectively attenuated the effects mediated by the α1-adrenoceptor, but not by 5-HT2AR. Disruption of caveolae decreased 5-HT2AR-mediated Src phosphorylation, but not α1-adrenoceptor-mediated Src phosphorylation. Finally, the PKC inhibitor GO6976 blocked Src phosphorylation by the α1-adrenoceptor, but not by 5-HT2AR. 5-HT2AR-mediated Kv inhibition and vasoconstriction are dependent on caveolar integrity and Src tyrosine kinase, but not on PKC. In contrast, α1-adrenoceptor-mediated Kv inhibition and vasoconstriction are not dependent on caveolar integrity, but rather on PKC and Src tyrosine kinase. Caveolae-independent PKC is upstream of Src activation for α1-adrenoceptor-mediated Kv inhibition and vasoconstriction. [Display omitted]