QUICK SEARCH:

[advanced]

	Author:		Keyword(s):

Home Help Feedback Subscriptions Archive Search Table of Contents

	Help viewing high resolution images
	Return to article

(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 4. Expression of IP₃ receptor isoforms in nuclear (N) and cytosolic (C) fractions of myotubes and their distribution in isolated nuclei. (A) Nuclear and cytosolic fractions of cultured myotubes bind [³H]IP₃ with a K_d 82.55±20.29 nM and 91.2±11.4 nM, respectively, and have a maximal binding capacity of 2.41 and 1.64±0.10 pmol/mg protein [see Scatchard plots (insets)]. The non-specific binding was measured in the presence of 2 µM cold IP₃. (B) Representative SDS-polyacrylamide gel analysis (from three independent preparations) of nuclear and cytosolic fractions. Type-1 IP₃R was enriched in the nuclear fraction, but was also present in the cytosolic fraction (upper panel); type-2 IP₃R was present only in the cytosolic fraction (middle panel), and type-3 IP₃R was enriched in the nuclear fraction, but was also present in the cytosolic fraction (bottom panel). In all cases the same concentration of protein was loaded. (C,D) Immunofluorescence of isolated myonuclei revealed that type-1 IP₃ receptor conserved the localization in the nuclear envelope (C) and that type-3 IP₃R was distributed with a speckled pattern in the nucleoplasm (D). Bar, 15 µm.

Return to article