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Vivek S. Peche Tad A. Holak Bhagyashri D. Burgute Kosmas Kosmas Sushant P. Kale F. Thomas Wunderlich Fatiha Elhamine Robert Stehle Gabriele Pfitzer Klaus Nohroudi Klaus Addicks Florian Stöckigt Jan W. Schrickel Julia Gallinger Michael Schleicher Angelika A. Noegel 《Cellular and molecular life sciences : CMLS》2013,70(3):527-543
Cyclase-associated proteins are highly conserved proteins that have a role in the regulation of actin dynamics. Higher eukaryotes have two isoforms, CAP1 and CAP2. To study the in vivo function of CAP2, we generated mice in which the CAP2 gene was inactivated by a gene-trap approach. Mutant mice showed a decrease in body weight and had a decreased survival rate. Further, they developed a severe cardiac defect marked by dilated cardiomyopathy (DCM) associated with drastic reduction in basal heart rate and prolongations in atrial and ventricular conduction times. Moreover, CAP2-deficient myofibrils exhibited reduced cooperativity of calcium-regulated force development. At the microscopic level, we observed disarrayed sarcomeres with development of fibrosis. We analyzed CAP2’s role in actin assembly and found that it sequesters G-actin and efficiently fragments filaments. This activity resides completely in its WASP homology domain. Thus CAP2 is an essential component of the myocardial sarcomere and is essential for physiological functioning of the cardiac system, and a deficiency leads to DCM and various cardiac defects. 相似文献
145.
Benjamin Förthmann Hella Brinkmann Andreas Ratzka Michal K. Stachowiak Claudia Grothe Peter Claus 《Cellular and molecular life sciences : CMLS》2013,70(14):2555-2568
Reduced levels of survival of motoneuron (SMN) protein lead to spinal muscular atrophy, but it is still unknown how SMN protects motoneurons in the spinal cord against degeneration. In the nucleus, SMN is associated with two types of nuclear bodies denoted as gems and Cajal bodies (CBs). The 23 kDa isoform of fibroblast growth factor-2 (FGF-223) is a nuclear protein that binds to SMN and destabilizes the SMN-Gemin2 complex. In the present study, we show that FGF-223 depletes SMN from CBs without affecting their general structure. FRAP analysis of SMN-EGFP in CBs demonstrated that the majority of SMN in CBs remained mobile and allowed quantification of fast, slow and immobile nuclear SMN populations. The potential for SMN release was confirmed by in vivo photoconversion of SMN-Dendra2, indicating that CBs concentrate immobile SMN that could have a specialized function in CBs. FGF-223 accelerated SMN release from CBs, accompanied by a conversion of immobile SMN into a mobile population. Furthermore, FGF-223 caused snRNP accumulation in CBs. We propose a model in which Cajal bodies store immobile SMN that can be mobilized by its nuclear interaction partner FGF-223, leading to U4 snRNP accumulation in CBs, indicating a role for immobile SMN in tri-snRNP assembly. 相似文献
146.
Arsenite but not oxamate produce in vitro a distinct depression of estrogen-dominated uterine motility, both in the absence of substrate as well as in the presence of exogenous glucose or lactate. The addition of oxamate to preparations suspended in a medium with lactate as the sole external substrate ameliorates the depression of uterine motility elicited by arsenic. 相似文献
147.
A crude extract of the sciatic nerve, eluate of dialyzed nerve extract or 2 folin-positive sephadex fractions induced acetylcholine sensitivity of extrajunctional regions in extensor digitorum longus muscle fibres of the rat, when released from silastic plates implanted for 3--4 days onto the muscle surface. 相似文献
148.
Octopamine content of the head of the locust Locusta migratoria has been determined during the last larval stage, moulting and adult life of 3 groups of insects: female and male gregarious, solitary and CO2 solitarized. An important difference was found between these 3 groups. Octopamine contents increased in the middle of the larval life and during the adult life. The moulting time is characterized by a sharp decrease of the octopamine content which becomes identical in the 3 groups of insects. The relation between octopamine content, hormone cycles and motility is discussed. 相似文献
149.
The immunofluorescent staining of the human parathyroid glands shows that the principal cells bind antimyosin-like antibodies. The presence of a myosin-like protein in the principal cells of the human parathyroid glands is presumably in rapport with parathormone secretion. 相似文献
150.
The effects of prostacyclin (PGI2) on the contractile frequency and on the isometric developed tension of spontaneously beating or paced isolated rat atria were explored. PGI2 enhanced frequency and contractile tension, both effects being blocked by the presence of propranolol, or following a pretreatment with 6-OHDopamine. 相似文献