| Name: | Mouse Monoclonal Antibody to Calretinin |
| Immunogen: | Full-length recombinant human protein expressed in and purified from E. coli. |
| HGNC Name: | CALB2 |
| UniProt: | P22676 |
| Molecular Weight: | 29kDa |
| Host: | Mouse |
| Isotype: | IgG1 |
| Species Cross-Reactivity: | Human, Rat, Mouse |
| RRID: | AB_2572242 |
| Format: | Purified antibody at 1mg/mL in 50% PBS, 50% glycerol plus 5mM NaN3 |
| Applications: | WB, IF/ICC, IHC |
| Recommended Dilutions: | WB: 1:1,000-1:5,000. IF/ICC or IHC: 1:1,000-2,000. |
| Storage: | Stable at 4°C for one year, for longer term store at -20°C |
Immunofluorescent analysis of rat cerebellum section stained with mouse mAb to calretinin, MCA-3G9, dilution 1:500 in green, and costained with chicken pAb to calbindin, CPCA-Calb, dilution 1:2,000 in red. Following transcardial perfusion of rat with 4% paraformaldehyde, brain was post fixed for 24 hours, cut to 45μM, and free-floating sections were stained with the above antibodies. The calretinin antibody labels interneurons in the granule cell layer, while the calbindin antibody stains Purkinje neurons and their dendritic processes in the molecular layer of the cerebellum.
Western blot analysis of rodent whole brain lysates using mouse mAb to calretinin, MCA-3G9, dilution 1:1,000. Lane 1 shows molecular weight standards in red and lanes 2 and 3 show rat and mouse brain lysates respectively. A single clean band running at 29kDa corresponds to the calretinin protein.
Mouse Monoclonal Antibody to Calretinin
Cat# MCA-3G9
$120.00 – $800.00
Calretinin, as the name suggests, was originally isolated in the retina but was found to be also expressed in mammalian central nerve system, testis, fallopian tube and pancreas (1). It is a cytoplasmic Calcium binding protein which includes typical “EF hand” structures the prototype for which is the protein parvalbumin (2-4). In the brain calretinin it is localized in certain classes of neurons, and antibodies to it are useful for identifying specific neuronal cell types (1). It is particularly concentrated in some cerebellar granular cells and their parallel fibres, but is also found in many GABAergic interneurons in the cortex. These GABAergic interneurons in most cases express only one of three related Calcium binding proteins, namely calretinin, calbindin or parvalbumin (5,6). As a result these important inhibitory interneurons can be identified and classified based on their content of these three proteins. Each type of neuron as defined in this fashion has distinct electrophysiological and functional properties (7). Calretinin deficiency in the mossy cells of the mouse dentate gyrus and granule cells results in abnormal excitability in the cerebellar neuronal network and impairment of long-term potentiation and motor coordination, suggesting that calretinin functions as a general Calcium buffer (8).
The MCA-3G9 antibody was made against full length recombinant human calretinin expressed in and purified from E. coli. The calretinin protein is related in amino acid sequence to calbindin and to a lesser extent parvalbumin and secretagogin, so, for studies of GABAergic interneurons, it is important to verify that antibodies developed against one protein do not cross react with either of the others, which we have done for MCA-3G9 using appropriate recombinant human proteins, see under “additional info” tag. We manufacture another mouse monoclonal antibody to calretinin MCA-6A9, a rabbit polyclonal RPCA-Calret and a chicken polyclonal CPCA-Calret. We also supply a variety of other mouse, rabbit and chicken antibodies to calbindin (MCA-4H7, MCA-5A9 and CPCA-Calb) and parvalbumin (MCA-3C9 and CPCA-Pvalb), allowing double and triple labeling of appropriate cell and tissue samples. Mouse select image at left for larger view.
Chromogenic immunostaining of a NBF fixed paraffin embedded human brain cortex section with mouse mAb to calretinin, MCA-3G9, dilution 1:2,000, detected with DAB (brown) using the Vector Labs ImmPRESS method and reagents with citra buffer retrieval. Hematoxylin (blue) was used as the counterstain. In this image, calretinin strongly stains the nucleus and cytoplasm of pyramidal neurons. The MCA-3G9 antibody performs well in testing with both 4% PFA and standard NBF fixed tissues but does not stain long term NBF fixed tissue effectively. Mouse select image for larger view.
Western blot analysis of recombinant protein preparations with mouse mAb to calretinin, MCA-3G9, dilution 1:1,000: Lane 1 shows protein molecular weight standards. The remaining lanes show equal amounts of recombinant full length human calbindin [2], calretinin [3], parvalbumin [4] and secretogogin [5]. This antibody reacts only with calretinin, and does not bind to the other structurally and functionally related calcium binding proteins.
1. Rogers JH. Calretinin: a gene for a novel calcium-binding protein expressed principally in neurons. J. Cell Biol. 105:1343-53 (1987).
2. Kretsinger RH, Nockolds CE. Carp Muscle Calcium-binding Protein: II. Structure determination and general description. J. Biol. Chem. 248:3313-26 (1973).
3. Andressen C, Bliimcke I, Celio MR. Calcium-binding proteins: selective markers of nerve cells. Cell Tissue Res. 271:181-208 (1993).
4. Schwaller B, Meyer M, Schiffmann S. ‘New’ functions for ‘old’ proteins: The role of the calcium binding proteins calbindin D-28k, calretinin and parvalbumin, in cerebellar physiology. Studies with knockout mice. The Cerebellum 1:241–58 (2002).
5. Condé F, et al. Local circuit neurons immunoreactive for calretinin, calbindin D‐28k or parvalbumin in monkey prefronatal cortex: Distribution and morphology. J. Comp. Neurol. 341:95-116 (1994).
6. Hof PR, et al. Cellular distribution of the calcium-binding proteins parvalbumin, calbindin, and calretinin in the neocortex of mammals: phylogenetic and developmental patterns. J. Chem. Neuroanat. 16:77-116 (1999).
7. Bearzatto B, et al. Mono- and dual-frequency fast cerebellar oscillation in mice lacking parvalbumin and/or calbindin D-28k. Eur. J. Neurosci. 22:861-70 (2005).
8. Schiffmann SN, et al. Impaired motor coordination and Purkinje cell excitability in mice lacking calretinin. PNAS 27:5257-62 (1999).
