Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs.
Liberation of Ca(2+) from the endoplasmic reticulum (ER) through inositol trisphosphate receptors (IP(3)R) is modulated by the ER Ca(2+) content, and overexpression of SERCA2b to accelerate Ca(2+) sequestration into the ER has been shown to potentiate the frequency and amplitude of IP(3)-evoked Ca(2...
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| Format: | Journal article |
| Language: | English |
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2011
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| _version_ | 1797061727243730944 |
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| author | Yamasaki-Mann, M Parker, I |
| author_facet | Yamasaki-Mann, M Parker, I |
| author_sort | Yamasaki-Mann, M |
| collection | OXFORD |
| description | Liberation of Ca(2+) from the endoplasmic reticulum (ER) through inositol trisphosphate receptors (IP(3)R) is modulated by the ER Ca(2+) content, and overexpression of SERCA2b to accelerate Ca(2+) sequestration into the ER has been shown to potentiate the frequency and amplitude of IP(3)-evoked Ca(2+) waves in Xenopus oocytes. Here, we examined the effects of SERCA overexpression on the elementary IP(3)-evoked puffs to elucidate whether ER [Ca(2+)] may modulate IP(3)R function via luminal regulatory sites in addition to simply determining the size of the available store and electrochemical driving force for Ca(2+) release. SERCA2b and Ca(2+) permeable nicotinic plasmalemmal channels were expressed in oocytes, and hyperpolarizing pulses were delivered to induce Ca(2+) influx and thereby load ER stores. Puffs evoked by photoreleased IP(3) were significantly potentiated in terms of numbers of responding sites, frequency and amplitude following transient Ca(2+) influx in SERCA-overexpressing cells, whereas little change was evident with SERCA overexpression alone or following Ca(2+) influx in control cells not overexpressing SERCA. Intriguingly, we observed the appearance of a new population of puffs that arose after long latencies and had prolonged durations supporting the notion of luminal regulation of IP(3)R gating kinetics. |
| first_indexed | 2024-03-06T20:35:24Z |
| format | Journal article |
| id | oxford-uuid:3273eda4-bb60-4dda-bd0f-ac51be8357d2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:35:24Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:3273eda4-bb60-4dda-bd0f-ac51be8357d22022-03-26T13:14:08ZEnhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3273eda4-bb60-4dda-bd0f-ac51be8357d2EnglishSymplectic Elements at Oxford2011Yamasaki-Mann, MParker, ILiberation of Ca(2+) from the endoplasmic reticulum (ER) through inositol trisphosphate receptors (IP(3)R) is modulated by the ER Ca(2+) content, and overexpression of SERCA2b to accelerate Ca(2+) sequestration into the ER has been shown to potentiate the frequency and amplitude of IP(3)-evoked Ca(2+) waves in Xenopus oocytes. Here, we examined the effects of SERCA overexpression on the elementary IP(3)-evoked puffs to elucidate whether ER [Ca(2+)] may modulate IP(3)R function via luminal regulatory sites in addition to simply determining the size of the available store and electrochemical driving force for Ca(2+) release. SERCA2b and Ca(2+) permeable nicotinic plasmalemmal channels were expressed in oocytes, and hyperpolarizing pulses were delivered to induce Ca(2+) influx and thereby load ER stores. Puffs evoked by photoreleased IP(3) were significantly potentiated in terms of numbers of responding sites, frequency and amplitude following transient Ca(2+) influx in SERCA-overexpressing cells, whereas little change was evident with SERCA overexpression alone or following Ca(2+) influx in control cells not overexpressing SERCA. Intriguingly, we observed the appearance of a new population of puffs that arose after long latencies and had prolonged durations supporting the notion of luminal regulation of IP(3)R gating kinetics. |
| spellingShingle | Yamasaki-Mann, M Parker, I Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs. |
| title | Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs. |
| title_full | Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs. |
| title_fullStr | Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs. |
| title_full_unstemmed | Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs. |
| title_short | Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs. |
| title_sort | enhanced er ca2 store filling by overexpression of serca2b promotes ip3 evoked puffs |
| work_keys_str_mv | AT yamasakimannm enhancederca2storefillingbyoverexpressionofserca2bpromotesip3evokedpuffs AT parkeri enhancederca2storefillingbyoverexpressionofserca2bpromotesip3evokedpuffs |