AKAP150 is required for stuttering persistent Ca2+ sparklets and angiotensin II-induced hypertension

Circ Res. 2008 Feb 1;102(2):e1-e11. doi: 10.1161/CIRCRESAHA.107.167809. Epub 2008 Jan 3.

Abstract

Hypertension is a perplexing multiorgan disease involving renal primary pathology and enhanced angiotensin II vascular reactivity. Here, we report that a novel form of a local Ca2+ signaling in arterial smooth muscle is linked to the development of angiotensin II-induced hypertension. Long openings and reopenings of L-type Ca2+ channels in arterial myocytes produce stuttering persistent Ca2+ sparklets that increase Ca2+ influx and vascular tone. These stuttering persistent Ca2+ sparklets arise from the molecular interactions between the L-type Ca2+ channel and protein kinase Calpha at only a few subsarcolemmal regions in resistance arteries. We have identified AKAP150 as the key protein, which targets protein kinase Calpha to the L-type Ca2+ channels and thereby enables its regulatory function. Accordingly, AKAP150 knockout mice (AKAP150-/-) were found to lack persistent Ca2+ sparklets and have lower arterial wall intracellular calcium ([Ca2+]i) and decreased myogenic tone. Furthermore, AKAP150-/- mice were hypotensive and did not develop angiotensin II-induced hypertension. We conclude that local control of L-type Ca2+ channel function is regulated by AKAP150-targeted protein kinase C signaling, which controls stuttering persistent Ca2+ influx, vascular tone, and blood pressure under physiological conditions and underlies angiotensin II-dependent hypertension.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins / deficiency
  • A Kinase Anchor Proteins / physiology*
  • Angiotensin II*
  • Animals
  • Calcium Channels, L-Type / metabolism
  • Calcium Signaling*
  • Hypertension / etiology*
  • Mice
  • Mice, Knockout
  • Protein Kinase C-alpha / metabolism
  • Vascular Resistance

Substances

  • A Kinase Anchor Proteins
  • Akap5 protein, mouse
  • Calcium Channels, L-Type
  • Angiotensin II
  • Protein Kinase C-alpha