PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2433530

Intracellular calcium-binding proteins: structure and possible functions.

C W Heizmann
View original source ↗Export metadata ↓

Abstract

The target proteins for calcium, when it acts as a second messenger, are a group of intracellular, specific calcium-binding proteins that contain EF-hand structures. Calmodulin regulates a number of Ca2+-dependent processes and is present in all eukaryotic cells. Parvalbumin, the S-100 proteins, two vitamin D-dependent Ca2+-binding proteins, and two tumor-associated proteins are present only in a few tissues and are there in distinct cell types serving more specific functions such as Ca2+-buffering or Ca2+-transport. The properties, distribution, and possible roles of these calcium-binding proteins in muscle, brain, and tumor cells are compared.

Explore related subjects

Calcium-Binding ProteinsCell LineCell Transformation, NeoplasticChromatography, High Pressure LiquidHistocytochemistryHumansMusclesNeuronsParvalbuminsS100 Calcium Binding Protein GS100 ProteinsJournal ArticleResearch Support, Non-U.S. Gov'tReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C W Heizmann. 1986. Intracellular calcium-binding proteins: structure and possible functions.. https://pubmed.ncbi.nlm.nih.gov/2433530/

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

KEEP EXPLORING

Related citations

PubMed2007

Regulation of the transport and protein levels of the inositol phosphorylceramide mannosyltransferases Csg1 and Csh1 by the Ca2+-binding protein Csg2.

Complex sphingolipids in yeast are known to function in cellular adaptation to environmental changes. One of the yeast complex sphingolipids, mannosylinositol phosphorylceramide (MIPC), is produced by the redundant inositol phosphorylceramide (IPC) mannosyltransferases Csg1 and Csh1. The Ca2+-binding protein Csg2 can form a complex with either Csg1 or Csh1 and is considered to act as a regulatory subunit. However, the role of Csg2 in MIPC synthesis has remained unclear. In this study, we found that Csg1 and Csh1 are N-glycosylated with core-type and mannan-type structures, respectively. Further identification of the glycosylated residues suggests that both Csg1 and Csh1 exhibit membrane topology with their C termini in the cytosol and their mannosyltransferase domains in the lumen. After complexing with Csg2, both Csg1 and Csh1 function in the Golgi, and then are delivered to the vacuole for degradation. However, uncomplexed Csh1 cannot exit from the endoplasmic reticulum. We also demonstrated that Ca2+ stimulates IPC-to-MIPC conversion, because of a Csg2-dependent increase in Csg1 levels. Thus, Csg2 has several regulatory functions for Csg1 and Csh1, including stability, transport, and gene expression.

Calcium-Binding Proteins↗
PubMed2007

Methylation analysis of the intergenic differentially methylated region of DLK1-GTL2 in human.

Imprinting is a non-Mendelian form of inheritance where epigenetic modifications control mono-allelic expression depending on the parental origin. Methylation of CpG-dinucleotides at differentially methylated regions (DMRs) is one of the best-studied mechanisms directing expression to one specific parental allele. We studied the methylation patterns of the intergenic (IG)-DMR of DLK1 and GTL2. The methylation marks of the IG-DMR were analysed in human gametes, preimplantation embryos, amniocytes and blood of babies born after intracytoplasmic sperm injection (ICSI) and blood from adults using a bisulphite sequencing technique. In oocytes, the IG-DMR was mainly unmethylated while in sperm cells a generally methylated pattern was detected. This germ-line specific methylation mark was maintained in the preimplantation embryos until the second cleavage stage. Afterwards in the preimplantation embryos, intermediate methylation patterns (26-74% methylation) occurred, which may point to relaxation of the imprints. Intermediate patterns were also present in amniocytes, blood from ICSI babies and adults. We hypothesise that in the early cleavage stage embryo a strict differential methylation pattern is needed for the correct imprint establishment of surrounding imprinted genes. Once correct imprinting of the involved gene(s) is acquired, a more relaxed state of the IG-region is allowed.

Calcium-Binding Proteins↗
PubMed2007

Secreted modular calcium-binding protein 2 haplotypes are associated with pulmonary function.

RATIONALE: Previously reported linkage to FEV(1) (LOD score = 5.0) on 6q27 in the Framingham Heart Study (FHS) led us to explore a candidate gene, SMOC2, at 168.6 Mb. OBJECTIVES: We tested association between SMOC2 polymorphisms and FEV(1) and FVC in unrelated FHS participants. METHODS: Twenty single-nucleotide polymorphisms (SNPs) around SMOC2 were genotyped in 1,734 subjects. MEASUREMENTS AND MAIN RESULTS: SNP data were analyzed using multiple linear regression models incorporating sex, age, body mass index, height, and smoking history as covariates, and analyses were repeated within strata of ever- and never-smokers. The minor allele of SNP rs1402 was associated with higher mean FEV(1) (p = 0.003) and FVC (p = 0.02) measures. In never-smoking subjects, association with higher measures was observed with the minor allele of rs747995 (FEV(1), p = 0.0006; FVC, p = 0.0008). These two SNPs lie in different haplotype blocks and reside in intron 4 of SMOC2. Haplotype analysis revealed a common G-T haplotype (rs747995-rs1402) with 77% frequency in never-smoking FHS subjects. The G-T haplotype was associated with reduction of 126 ml for FEV(1) (p = 0.0002) and 157 ml for FVC (p = 0.0002). The G-T haplotype was similarly associated in a set of never-smoking subjects from the Family Heart Study (FEV(1), p = 0.03; FVC, p = 0.03). CONCLUSIONS: The replication of the association in two populations supports the possibility that SMOC2 might play an important role in the determination of FEV(1) and FVC.

Calcium-Binding Proteins↗