BackgroundMoyamoya disease is an idiopathic vascular disorder of intracranial arteries. Its susceptibility locus has been mapped to 17q25.3 in Japanese families, but the susceptibility gene is unknown.Methodology/Principal FindingsGenome-wide linkage analysis in eight three-generation families with moyamoya disease revealed linkage to 17q25.3 (P<10-4). Fine mapping demonstrated a 1.5-Mb disease locus bounded by D17S1806 and rs2280147. We conducted exome analysis of the eight index cases in these families, with results filtered through Ng criteria. There was a variant of p.N321S in PCMTD1 and p.R4810K in RNF213 in the 1.5-Mb locus of the eight index cases. The p.N321S variant in PCMTD1 could not be confirmed by the Sanger method. Sequencing RNF213 in 42 index cases confirmed p.R4810K and revealed it to be the only unregistered variant. Genotyping 39 SNPs around RNF213 revealed a founder haplotype transmitted in 42 families. Sequencing the 260-kb region covering the founder haplotype in one index case did not show any coding variants except p.R4810K. A case-control study demonstrated strong association of p.R4810K with moyamoya disease in East Asian populations (251 cases and 707 controls) with an odds ratio of 111.8 (P = 10−119). Sequencing of RNF213 in East Asian cases revealed additional novel variants: p.D4863N, p.E4950D, p.A5021V, p.D5160E, and p.E5176G. Among Caucasian cases, variants p.N3962D, p.D4013N, p.R4062Q and p.P4608S were identified. RNF213 encodes a 591-kDa cytosolic protein that possesses two functional domains: a Walker motif and a RING finger domain. These exhibit ATPase and ubiquitin ligase activities. Although the mutant alleles (p.R4810K or p.D4013N in the RING domain) did not affect transcription levels or ubiquitination activity, knockdown of RNF213 in zebrafish caused irregular wall formation in trunk arteries and abnormal sprouting vessels.Conclusions/SignificanceWe provide evidence suggesting, for the first time, the involvement of RNF213 in genetic susceptibility to moyamoya disease.

The heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is a member of the EGF family of growth factors that binds to and activates the EGF receptor (EGFR) and the related receptor tyrosine kinase, ErbB4. HB-EGF-null mice (HB del/del ) were generated to examine the role of HB-EGF in vivo. More than half of the HB del/del mice died in the first postnatal week. The survivors developed severe heart failure with grossly enlarged ventricular chambers. Echocardiographic examination showed that the ventricular chambers were dilated and that cardiac function was diminished. Moreover, HB del/del mice developed grossly enlarged cardiac valves. The cardiac valve and the ventricular chamber phenotypes resembled those displayed by mice lacking EGFR, a receptor for HB-EGF, and by mice conditionally lacking ErbB2, respectively. HB-EGF-ErbB interactions in the heart were examined in vivo by administering HB-EGF to WT mice. HB-EGF induced tyrosine phosphorylation of ErbB2 and ErbB4, and to a lesser degree, of EGFR in cardiac myocytes. In addition, constitutive tyrosine phosphorylation of both ErbB2 and ErbB4 was significantly reduced in HB del/del hearts. It was concluded that HB-EGF activation of receptor tyrosine kinases is essential for normal heart function. The ErbB family of receptor tyrosine kinases have fundamental roles in development, proliferation, and differentiation (1). There are four members of the receptor tyrosine kinase ErbB family, EGFR͞ErbB1͞HER1, ErbB2͞HER2͞neu, ErbB3͞HER3, and ErbB4͞HER4. Epidermal growth factor (EGF) family ligands bind to and activate their receptors by inducing the formation of homodimers and heterodimers, resulting in autophosphorylation of specific tyrosine residues within the cytoplasmic domain. The phosphorylated tyrosine residues bind adapter proteins, which are instrumental in mediating downstream signaling pathways that determine the biological activity of the ErbB family of ligands.In vertebrates, the EGF family of ligands bind to ErbB receptors with some degree of preference. EGF, transforming growth factor-␣, and amphiregulin bind to EGF receptor (EGFR); heparin-binding EGF-like growth factor (HB-EGF), epiregulin, and betacellulin bind to both EGFR and ErbB4; NRG-1 (neuregulin͞heregulin͞NDF) and NRG-2 bind to ErbB3 and ErbB4; and NRG-3 and NRG-4 bind to ErbB4 but not to ErbB3. Although no ligand for ErbB2 has yet been described, ErbB2 is active as a signaling receptor by forming heterodimers with other ErbB receptors (2).HB-EGF is synthesized as a type I transmembrane protein (proHB-EGF) composed of signal peptide, heparin-binding, EGF-like, juxtamembrane, transmembrane, and cytoplasmic domains (3, 4). The membrane-bound proHB-EGF is cleaved at the juxtamembrane domain, resulting in the shedding of soluble HB-EGF (5). The full-length proHB-EGF is biologically active as a juxtacrine growth factor that signals neighboring cells in a nondiffusible manner (6-8). ProHB-EGF forms complexes with CD9 (9) and integrin ␣3␤1 (10) on the cell membrane. ProHB-EGF is al...

AMP-activated protein kinase (AMPK) is an energy-sensing Ser/Thr protein kinase originally shown to be regulated by AMP. AMPK is activated by various cellular stresses that inhibit ATP production or stimulate ATP consumption. In addition to its role in metabolism, AMPK has recently been reported to reshape cells by regulating cell polarity and division. However, the downstream targets of AMPK that participate in these functions have not been fully identified. Here, we show that phosphorylation of the microtubule plus end protein CLIP-170 by AMPK is required for microtubule dynamics and the regulation of directional cell migration. Both inhibition of AMPK and expression of a non-phosphorylatable CLIP-170 mutant resulted in prolonged and enhanced accumulation of CLIP-170 at microtubule tips, and slower tubulin polymerization. Furthermore, inhibition of AMPK impaired microtubule stabilization and perturbed directional cell migration. All of these phenotypes were rescued by expression of a phosphomimetic CLIP-170 mutant. Our results demonstrate, therefore, that AMPK controls basic cellular functions by regulating microtubule dynamics through CLIP-170 phosphorylation.

Natriuretic peptides enhance adiponectin production by human adipocytes in vitro and even in patients with CHF, which might have a beneficial effect on cardiomyocytes in patients receiving recombinant natriuretic peptide therapy for heart failure.

Neuropilin‐1 (NRP1) is a co‐receptor for vascular endothelial growth factor (VEGF) that enhances the angiogenic signals cooperatively with VEGFR2. VEGF signaling is essential for physiological and pathological angiogenesis through its effects on vascular endothelial cells (ECs) and smooth muscle cells (SMCs), but the mechanisms coordinating this response are not well understood. Here we show that a substantial fraction of NRP1 is proteoglycan modified with either heparan sulfate or chondroitin sulfate on a single conserved Ser. The composition of the NRP1 glycosaminoglycan (GAG) chains differs between ECs and SMCs. Glycosylation increased VEGF binding in both cell types, but the differential GAG composition of NRP1 mediates opposite responsiveness to VEGF in ECs and SMCs. Finally, NRP1 expression and its GAG modification post‐transcriptionally regulate VEGFR2 protein expression. These findings indicate that GAG modification of NRP1 plays a critical role in modulating VEGF signaling, and may provide new insights into physiological and pathological angiogenesis.