85-1401-45　HCN4, Rat Control Peptide (Hyperpolarization-activated Cyclic Nucleotide-gated channel 4) 100ug　H1827-30H

特徴

• A 15-aa peptide sequence, mapping near the cytoplasmic, C-terminus of rat HCN4 .
• Biological rhythms (beating of the heart, circadian sleep cycles, respiration, and the release of hormones) are necessary to sustain life. Heart beating is the most reliable and rhythmic biological phenomenon. Cardiac pacemaking is produced by the slow diastolic depolarization phase of the action potential. The hyperpolarization-activated cation current (termed If, Ih, or Iq) plays a key role in the in the initiation and modulation of cardiac and neuronal pacemaker depolarization. The generation of cardiac pacemaker potentials relies on a complex interplay between at least four different types of cation channels: T- and L-type Ca2+ channels, K+ channels, and a cation channel termed If (synonymous names are Ih and Iq). The If channel has been designated as "pacemaker" channel because it reveals unique features that are believed to be a prerequisite for pacemaker activity. Recently, the hyperpolarization-activated cyclic nucleotide-gated families of ion channel proteins (HCN1-4) have been identified as the "pacemaker" channel. The amino acid sequences of HCNs predict a structure similar to that of voltage-gated (Kv) channels and cyclic nucleotide-gated (CNG) channels. HCNs proteins (HCN1-4) are characterized by six transmembrane domains (S1-S6), including a including a positively charged voltage-sensing S4 segment and an ion-conducting pore between S5 and S6. In the C terminus the HCNs carry a cyclic nucleotide-binding domain (CNBD), a motif found in several cyclic nucleotide-binding proteins. The core region of HCNs channels (S1 to the C terminus of the CNBD) is highly conserved, whereas the cytoplasmic N and C-termini, vary considerably in their length and share only weak sequence homology. The functional HCN, like other members of the superfamily of voltage-gated cation channels, channels probably assemble into tetrameric complexes.
• HCN4 (rat 1198 aa, human 1203-aa, chromosome 15q24-q25) is highly expressed at heart ventricle and atrium, brain (olfactory bulb, thalamus), and testis. expressed in brain.