PubMed HealthSearch

PubMed · 6281080

Calmodulin: an overview.

Abstract

Calmodulin is a 16,700-dalton Ca2+-binding protein ubiquitous in the eukaryotes. It has no intrinsic enzymatic activity, but it regulates a wide spectrum of enzymes that control many basic cellular processes, ranging from the metabolism of cyclic nucleotides, Ca2+, and glycogen to contractile activity and stimulus-secretion coupling. Mounting evidence now indicates that calmodulin is the major intracellular Ca2+ receptor that remained elusive despite three decades of extensive work by many investigators.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

W Y Cheung. 1982. Calmodulin: an overview.. https://pubmed.ncbi.nlm.nih.gov/6281080/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Expression of glutamate transporters in the adult bovine corpus callosum.

The presence and distribution of the glutamate transporters, EAAC1, GLAST and GLT-1, were examined in the adult bovine corpus callosum by means of Western blotting and immunohistochemistry. We found GLAST to be expressed in oligodendrocytes and in some astrocytes. GLT-1 was located throughout the processes of fibrous astrocytes. In addition, EAAC1 was present in a small population of cells that are probably adult oligodendrocyte progenitor cells.

2',3'-Cyclic-Nucleotide Phosphodiesterases

Cloning and characterization of zRICH, a 2',3'-cyclic-nucleotide 3'-phosphodiesterase induced during zebrafish optic nerve regeneration.

We previously reported cloning of cDNAs encoding both components of a protein doublet induced during goldfish optic nerve regeneration. The predicted protein sequences showed significant homology with the mammalian 2',3'-cyclic-nucleotide 3'-phosphodiesterases (CNPases). CNPases are well-established markers of mammalian myelin; hence, the cDNAs were designated gRICH68 and gRICH70 (for goldfish Regeneration-Induced CNPase Homologues of 68 and 70 kDa). Homologous cDNAs have now been isolated from zebrafish encoding a highly related protein, which we have termed zRICH. RNase protection assays show that zRICH mRNA is induced significantly (fivefold) in optic nerve regenerating zebrafish retinas 7 days following nerve crush. Western blots show a single band in zebrafish brain and retina extracts, with immunoreactivity increasing three-fold in regenerating retinas 21 days postcrush. Immunohistochemical analysis indicated that this increase in zRICH protein expression is localized to the retinal ganglion cell layer in regenerating retina. We have characterized and evaluated the relevance of a conserved beta-ketoacyl synthase motif in zRICH to CNPase activity by means of site-directed mutagenesis. Two residues within the motif, H334 and T336, are critical for enzymatic activity. A cysteine residue within the motif, which corresponds to a critical residue for beta-ketoacyl synthase, does not appear to participate in the phosphodiesterase activity.

2',3'-Cyclic-Nucleotide Phosphodiesterases

Establishment of primary vestibular schwannoma cultures from neurofibromatosis type-2 patients.

Primary cultures were established from vestibular schwannomas of NF2 patients. The cultured tumor cells were selectively amplified by growth factor supplemented medium and characterized by immunocytochemistry. NF2 cDNA was amplified by RT-PCR and mutations were detected by both the non-isotopic RNase cleavage assay and direct DNA sequencing, no detectable wild-type NF2 transcript was found in cDNA from the cultured cells. Distinguishable morphology and growth rate differences have been observed in different passages of the primary cells. The data suggest that a pure schwannoma primary culture can be established and could be very useful in vitro model for further understanding the NF2 gene function in Schwann cells.

2',3'-Cyclic-Nucleotide Phosphodiesterases