How to Subdue a Swelling Heart

Marx, J.-S.

doi:10.1126/science.300.5625.1492

Cited by 5 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increase in energy transfer efficiency observed in the presence of the Ca-ATPase is largely the result of the enhanced quantum yield of PMal, and the associated increase in the Fo ¨rster distance (R o ) that defines the efficiency of energy transfer. Thus, the average spatial separation between PMal bound to Cys 24 and nitroTyr 6 (as measured for bound PLB) is about 18 Å (Table 1), consistent with previous NMR measurements of PLB in organic cosolvents (1FJK PDB; ref 9). These results suggest that the overall dimensions of the cytosolic domain of PLB are not significantly affected by association with the Ca-ATPase.…”

Section: Functional Reconstitution Of Engineered and Derivatizedsupporting

confidence: 89%

“…Specific DeriVitization of PLB. The chemical modification of the single Cys 24 with PMal and the nitration of the single Tyr 6 with tetranitromethane (TNM) was carried out as previously described (17). Before modification of Cys 24 with PMal, PLB was incubated in the presence of 50 mM K 2 PO 4 (pH 7.2), 50 mM DTT, and 0.1% C 12 E 9 for 3 h at room Fluorescence Measurements.…”

Section: Materials N-(1-pyrenylmentioning

confidence: 99%

“…Specifically, the calcium concentration necessary for one-half-maximal activation (i.e., [Ca 1/2 ]) for the reconstituted preparation ([Ca 1/2 ] ) 0.66 ( 0.02 µM) is virtually identical to that observed for cardiac SR ([Ca 1/2 ] ) 0.64 ( 0.02 µM) and upon release of the inhibitory interaction between PLB and the Ca-ATPase following addition of PKA, there is a similar shift in the calcium concentration dependence of activation toward lower calcium concentrations (i.e., ∆Ca 1/2 ) 0.3 µM). Thus, measurements of the spatial separation between PMal and nitroTyr 6 will provide reliable information regarding the inhibitory interaction between PLB and the Ca-ATPase.…”

Section: Functional Reconstitution Of Engineered and Derivatizedmentioning

confidence: 99%

“…Frequency-domain fluorescence spectroscopy was used to measure the intensity decay of PMal bound to Cys 24 in PLB in the absence and presence of nitroTyr 6 (Figure 4). Data were collected at 20 frequencies between 0.4 and 200 MHz.…”

Section: Functional Reconstitution Of Engineered and Derivatizedmentioning

confidence: 99%

See 3 more Smart Citations

Phospholamban Binds in a Compact and Ordered Conformation to the Ca-ATPase

Xiong

Bigelow

et al. 2003

Biochemistry

View full text Add to dashboard Cite

Mutagenesis and cross-linking measurements have identified specific contact interactions between the cytosolic and the transmembrane sequences of phospholamban (PLB) and the Ca-ATPase, and in conjunction with the high-resolution structures of PLB and the Ca-ATPase, have been used to construct models of the PLB-ATPase complex, which suggest that PLB adopts a more extended structure within this complex. To directly test these predictions, we have used fluorescence resonance energy transfer to measure the average conformation and heterogeneity between chromophores covalently bound to the transmembrane and cytosolic domains of PLB reconstituted in proteoliposomes. In the absence of the Ca-ATPase, the cytosolic domain of PLB assumes a wide range of structures relative to the transmembrane sequence, which can be described using a model involving a Gaussian distribution of distances with an average distance (Rav) of less than 21 A and a half-width (HW) of 36 A. This conformational heterogeneity of PLB is consistent with the 10 structures resolved by NMR for the C41F mutant of PLB in organic cosolvents. In contrast, PLB bound to the Ca-ATPase assumes a unique and highly ordered conformation, where Rav = 14.0 +/- 0.3 A and HW = 3.7 +/- 0.6 A. The small spatial separation between the bound chromophores on PLB is inconsistent with an extended conformation of bound PLB in current models. Thus, to satisfy known interaction sites of PLB and the Ca-ATPase, these findings suggest a reorientation of the nucleotide binding domain of the Ca-ATPase toward the bilayer surface to bring known PLB binding sites into close juxtaposition with residues near the amino-terminus of PLB. Induction of an altered conformation of the nucleotide binding domain of the Ca-ATPase by PLB binding is suggested to underlie the reduced calcium sensitivity associated with PLB inhibition of the pump.

show abstract

Section: Functional Reconstitution Of Engineered and Derivatizedsupporting

confidence: 89%

Section: Materials N-(1-pyrenylmentioning

confidence: 99%

Section: Functional Reconstitution Of Engineered and Derivatizedmentioning

confidence: 99%

Section: Functional Reconstitution Of Engineered and Derivatizedmentioning

confidence: 99%

See 2 more Smart Citations

Phospholamban Binds in a Compact and Ordered Conformation to the Ca-ATPase

Xiong

Bigelow

et al. 2003

Biochemistry

View full text Add to dashboard Cite

show abstract

“…Among the variable causes of HCM and DCM, heritable gene mutations have only been recently integrated into the classification system of underlying etiologies of congestive heart failure. Indeed, the recognition that many primary cardiomyopathies are familial disorders has highlighted that heart failure is the result of a complex interplay among genetic factors, molecular modifiers, and environmental stimuli and has considerably shifted the focus of current research toward human molecular genetics (25,32,39,71,86).…”

mentioning

confidence: 99%

Array lessons from the heart: focus on the genome and transcriptome of cardiomyopathies

Sanoudou

Vafiadaki

Arvanitis

et al. 2005

Physiological Genomics

View full text Add to dashboard Cite

Our understanding of the cardiovascular system has evolved through the years by extensive studies emphasizing the identification of the molecular and physiological mechanisms involved in its normal function and disease pathogenesis. Major discoveries have been made along the way. However, the majority of this work has focused on specific genes or pathways rather than integrative approaches. In cardiomyopathies alone, over 30 different loci have shown mutations with varying inheritance patterns, yet mostly coding for structural proteins. The emergence of microarrays in the early 1990s paved the way to a new era of cardiovascular research. Microarrays dramatically accelerated the rhythm of discoveries by giving us the ability to simultaneously study thousands of genes in a single experiment. In the field of cardiovascular research, microarrays are having a significant contribution, with the majority of work focusing on end-stage cardiomyopathies that lead to heart failure. Novel molecular mechanisms have been identified, known pathways are seen under new light, disease subgroups begin to emerge, and the effects of various drugs are molecularly dissected. This cross-study data comparison concludes that consistent energy metabolism gene expression changes occur across dilated, hypertrophic, and ischemic cardiomyopathies, while Ca2+ homeostasis changes are prominent in the first two cardiomyopathies, and structural gene expression changes accompany mostly the dilated form. Gene expression changes are further correlated to disease genetics. The future of microarrays in the cardiomyopathy field is discussed with an emphasis on optimum experimental design and on applications in diagnosis, prognosis, and drug discovery.

show abstract

Models of cardiac fibrosis

Rajamannan

2006

Drug Discovery Today: Disease Models

View full text Add to dashboard Cite

How to Subdue a Swelling Heart

Cited by 5 publications

References 0 publications

Phospholamban Binds in a Compact and Ordered Conformation to the Ca-ATPase

Phospholamban Binds in a Compact and Ordered Conformation to the Ca-ATPase

Array lessons from the heart: focus on the genome and transcriptome of cardiomyopathies

Models of cardiac fibrosis

Contact Info

Product

Resources

About