Subcellular localization of coagulation factor II receptor-like 1 in neurons governs angiogenesis

Abstract

Neurons have an important role in retinal vascular development. Here we show that the G protein-coupled receptor (GPCR) coagulation factor II receptor-like 1 (F2rl1, previously known as Par2) is abundant in retinal ganglion cells and is associated with new blood vessel formation during retinal development and in ischemic retinopathy. After stimulation, F2rl1 in retinal ganglion cells translocates from the plasma membrane to the cell nucleus using a microtubule-dependent shuttle that requires sorting nexin 11 (Snx11). At the nucleus, F2rl1 facilitates recruitment of the transcription factor Sp1 to trigger Vegfa expression and, in turn, neovascularization. In contrast, classical plasma membrane activation of F2rl1 leads to the expression of distinct genes, including Ang1, that are involved in vessel maturation. Mutant versions of F2rl1 that prevent nuclear relocalization but not plasma membrane activation interfere with Vegfa but not Ang1 expression. Complementary angiogenic factors are therefore regulated by the subcellular localization of a receptor (F2rl1) that governs angiogenesis. These findings may have implications for the selectivity of drug actions based on the subcellular distribution of their targets.

Sequences within the C Terminus of the Metabotropic Glutamate Receptor 5 (mGluR5) Are Responsible for Inner Nuclear Membrane Localization

“…For example, GPCRs have been found on mitochondria (6), endoplasmic reticulum (ER) membranes (7), lysosomes (8,9), and on nuclear membranes (10 -12). Certain GPCRs are even found within the nucleoplasm on nuclear bodies and/or nuclear invaginations (13)(14)(15)(16). Although many intracellular GPCRs are activated at the cell surface and subsequently trafficked to their intracellular site, others can be activated at their subcellular location via so-called intracrine ligands that can enter cells via diffusion or be made in situ, endocytosed, and/or transported through channels or pores (12,17,18).…”

“…Although many intracellular GPCRs are activated at the cell surface and subsequently trafficked to their intracellular site, others can be activated at their subcellular location via so-called intracrine ligands that can enter cells via diffusion or be made in situ, endocytosed, and/or transported through channels or pores (12,17,18). Intracellular GPCRs can also function independently governing processes such as synaptic plasticity (19), myocyte contraction (15), and angiogenesis (16). Collectively, the present findings reinforce the notion that intracellular GPCRs play a dynamic role in generating and shaping intracellular signaling pathways.…”

“…Certain INM proteins also contain an NLS, although mutation or deletion does not affect INM localization (20). Many peptide-activated GPCRs also use an NLS and karyopherins such as importin-␤1 for nuclear import after receptor activation on the cell surface (16). Inasmuch as these receptors are not associated with the INM but rather appear within the nucleoplasm itself (via unknown mechanisms), the nucleoplasm targeting motifs might be quite different.…”

Intranuclear Signaling Cascades Triggered by Nuclear GPCRs

“…In stimulated retinal ganglion cells, F2rl1 translocates from the plasma membrane to the cell nucleus, using a microtubule-dependent shuttle that requires sorting nexin 11, which contains a NLS motif [50]. Plasma membrane activation of F2rl1 induces the expression of several genes, including Ang1, that are involved in vessel maturation.…”

“…In contrast, nuclear F2rl1 facilitates recruitment of the transcription factor Sp1 to trigger Vegfa expression and, in turn, neovascularization (Table 1). Mutant constructs of F2rl1 that inhibit nuclear localization, but not plasma membrane activation, interfere with Vegfa expression [50].…”