- GST fusion protein with the sequence HGHLHDSAEE RRLIAEGDASPGEDRTPPGLAAEPERP, corresponding to amino acid residues 119-155 of human HCN4 (Accession Q9Y3Q4). Intracellular, N-terminus.
- Western blot analysis of rat brain lysate:1. Guinea pig Anti-HCN4 Antibody (#APC-052-GP), (1:200).
2. Guinea pig Anti-HCN4 Antibody, preincubated with HCN4 Blocking Peptide (#BLP-PC052).
- Expression of HCN4 in mouse thalamusImmunohistochemical staining of mouse thalamus using Guinea pig Anti HCN4 Antibody (#APC-052-GP). A. HCN4 staining (green) appears in the neuropil of the ventral posterior thalamic nucleus (VPL). B. Nuclear staining using DAPI as the counter stain (blue). C. Merged images of A and B.
- Multiplex staining of HCN4 and HCN2 in mouse thalamusImmunohistochemical staining of mouse thalamus frozen section using Guinea pig Anti-HCN4 Antibody (#APC-052-GP) and rabbit Anti-HCN2 Antibody (#APC-030). A. Staining of HCN4 (green) appears in the ventral posterior thalamic nucleus (VPL). B. In the same section as in A, staining of HCN2 (red) appears in the ventral posterior thalamic nucleus (VPL) and also in the reticular thalamic nucleus (RT). The area between these thalamic nuclei (star) is white matter and neither protein is expressed in that region. C. Merged images of A and B.
- Much, B. et al (2003) J.Biol.Chem. 278, 43781.
- Notomi, T. et al (2004) J. Comp. Neurol. 471, 241.
- Gravante, B. et al (2004) J.Biol.Chem. 279, 43847.
- Moosmang, S. et al. (2001) Eur. J. Biochem. 268, 1646.
- Garcia-Frigola, C. et al. (2003) Gene Expr Patterns 3, 777.
- Monteggia, L. et al. (2000) Molec. Brain Res. 1-2, 129.
Hyperpolarization-activated cation currents (Ih) appear in the heart and the brain and have a crucial role in controlling electrical pacemaker activity, contributing to biological processes such as heartbeat, sleep-wake cycle and synaptic plasticity.1,2
The Ih currents are generated by the Hyperpolarization-activated cyclic nucleotide-gated channel family (HCN), which is comprised of four homologous members, HCN1-4.
Each HCN subunit consists of six transmembrane domains (TM), a pore region between TM5-TM6 and a binding domain for cyclic nucleotides (CNBD) in the cytoplasmic C-terminus.2
The HCN subunits can form functional homomers and can also co-assemble into functional heteromers.2
The channels are closely related to each other and share a homology of about 60%. However, their similarity decreases in the cytoplasmic N- and C-termini. The HCN1-4 channels mainly differ from each other in their speed of activation and the extent to which they are modulated by cAMP. HCN1, weakly affected by cAMP, is the fastest channel, followed by HCN2, HCN3 and HCN4.
HCN4 is highly expressed in a restricted manner in adult sinoatrial (SA) node, constituting a good molecular marker for the adult cardiac pacemaker and might serve as a unique marker of the developing SA node .4,5
mRNA expression of HCN4 is most abundant in medial habenula and anterior and principal relay nuclei of the thalamus.6
Species reactivity key:
Guinea pig Anti-HCN4 Antibody (#APC-052-GP), raised in guinea pigs, is a highly specific antibody directed against an epitope of the human protein. The antibody can be used in western blot and immunohistochemistry applications. It has been designed to recognize HCN4 from human, rat and mouse samples. The antigen used to immunize guinea pigs is the same as Anti-HCN4 Antibody (#APC-052) raised in rabbit. Our line of guinea pig antibodies enables more flexibility with our products such as multiplex staining studies, immunoprecipitation, etc.