• 환경생물
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• 제41권1호
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• pp.54-59
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• 2023

Lovenia elongata is a member of the family Loveniidae and is one of the most common tropical echinoids. This species has a broad distribution range in the sub- and tropical regions of the Indo-Pacific Ocean, extending from the Mozambique to the Hawaiian Islands, and from southern Japan to northern Australia. It is commonly found in subtidal areas and on coral reefs within these regions. This species was for the first time recorded from the Ulleungdo Island, Korea. This species is characterized by a teardrop-shaped test that reaches up to 5 cm in length, with a deep groove at the front and tapered at the back end. The petaloid is not obvious, and the primary spines are long and banded. This study is the first to report the newly recorded L. elongata in Korea.

• Animal cells and systems
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• 제11권2호
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• pp.169-173
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• 2007

Hyperpolarization-activated nonselective cation channels (HCNs) play a pivotal role in producing rhythmic electrical activity in the heart and the nerve cells. In our previous experiments, voltage-dependent $Cd^{2+}$ access to one of the substituted cysteines in S6, T464C, supports the existence of an intracellular voltage-dependent activation gate. Direct binding of intracellular cAMP to HCN channels also modulates gating. Here we attempted to locate the cAMP-modulated structure that can modify the gating of HCN channels. SpHCN channels, a sea urchin homologue of the HCN family, became inactivated rapidly and intracellular cAMP removed this inactivation, resulting in about eight-fold increase of steady-state current level. T464C was probed with $Cd^{2+}$ applied to the intracellular side of the channel. We found that access of $Cd^{2+}$ to T464C was strongly gated by cAMP as well as voltage. Release of bound $Cd^{2+}$ by DMPS was also gated in a cAMP-dependent manner. Our results suggest the existence of an intracellular cAMP-modulated gate in the lower S6 region of spHCN channels.