| Literature DB >> 14751234 |
Hiroki Kasai1, Atsushi Yao, Tomomi Oyama, Hiroshi Hasegawa, Hiroshi Akazawa, Haruhiro Toko, Toshio Nagai, Koichiro Kinugawa, Osami Kohmoto, Kei Maruyama, Toshiyuki Takahashi, Ryozo Nagai, Atsushi Miyawaki, Issei Komuro.
Abstract
Although abnormal sarcoplasmic reticulum (SR) Ca(2+) handling may cause heart failure, there has been no method to directly measure Ca(2+) concentration in SR ([Ca(2+)](SR)) of living cardiomyocytes. We have measured [Ca(2+)](SR) by expressing novel fluorescent Ca(2+) indicators yellow cameleon (YC) 2.1, YC3er, and YC4er in cultured neonatal rat cardiomyocytes. The distribution of YC2.1 was uniform in the cytoplasm, while that of YC3er/YC4er, containing the signal sequence which recruits them to SR, showed reticular pattern and was co-localized with SERCA2a. The treatment with caffeine reversibly decreased the emission ratio (R) in YC3er/YC4er-expressing myocytes, and the treatment with ryanodine and thapsigargin decreased R irreversibly. During the contraction-relaxation cycle, R was changed periodically in the YC2.1- and YC3er-expressing myocytes, but its direction of the change was opposite. These results suggest that YC3er/YC4er were specifically localized and functioned in SR as a [Ca(2+)](SR) indicator. This technique would be useful to understand the function of SR in failing myocardium.Entities:
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Year: 2004 PMID： 14751234 DOI： 10.1016/j.bbrc.2003.12.189
Source DB: PubMed Journal: Biochem Biophys Res Commun ISSN： 0006-291X Impact factor: 3.575