The carboxyl-terminal region common to lamins A and C contains a DNA binding domain.

Lamins A and C are intermediate filament proteins which polymerize into the nucleus to form the nuclear lamina network. The lamina is apposed to the inner nuclear membrane and functions in tethering chromatin to the nuclear envelope and in maintaining nuclear shape. We have recently characterized a globular domain that adopts an immunoglobulin fold in the carboxyl-terminal tail common to lamins A and C.

The Ig-like structure of the C-terminal domain of lamin A/C, mutated in muscular dystrophies, cardiomyopathy, and partial lipodystrophy.

Lamins are nuclear intermediate filaments that, together with lamin-associated proteins, maintain nuclear shape and provide a structural support for chromosomes and replicating DNA. We have determined the solution structure of the human lamin A/C C-terminal globular domain which contains specific mutations causing four different heritable diseases. This domain encompasses residues 430-545 and adopts an Ig-like fold of type s.

The uteroglobin fold.

Uteroglobin (UTG) forms a fascinating homodimeric structure that binds small- to medium-sized ligands through an internal hydrophobic cavity, located at the interface between the two monomers. Previous studies have shown that UTG fold is not limited to the UTG/CC10 family, whose sequence/structure relationships are highlighted here, but can be extended to the cap domain of Xanthobacter autotrophicus haloalkane dehalogenase. We show here that UTG fold is adopted by several other cap domains within the alpha/beta hydrolase family, making it a well-suited "geode" structure allowing it to sequester various hydrophobic molecules.

Evidence of enzymatic degradation of insulin-like growth factor-binding proteins in the 150K complex during pregnancy.

Western ligand blot analysis of the different molecular forms of insulin-like growth factor-binding protein IGF-BP) in serum and plasma samples from 89 pregnant women has revealed a marked decrease, after the second month of pregnancy, in the 41.5 and 38.5K species (which are the binding units of the 150K complex) as well as in the 24K form.

Regulation of binding proteins for insulin-like growth factors (IGF) in humans. Increased expression of IGF binding protein 2 during IGF I treatment of healthy adults and in patients with extrapancreatic tumor hypoglycemia.

Unlabelled: Insulin-like growth factors (IGFs) in blood form two complexes with specific binding proteins (BPs): a large, growth hormone (GH)-dependent complex with restricted capillary permeability, and a smaller complex, inversely related to GH, with high turnover of its IGF pool and free capillary permeability. The distribution of BPs and of IGFs I and II between these complexes was studied in sera from healthy adults treated with IGF I or/and GH and from patients with extrapancreatic tumor hypoglycemia. Like GH, IGF I administration raises IGF I and two glycosylation variants of IGFBP-3 in the large complex, but unlike GH drastically reduces IGF II.

Molecular forms of serum insulin-like growth factor (IGF)-binding proteins in man: relationships with growth hormone and IGFs and physiological significance.

Insulin-like growth factor-I (IGF-I) and IGF-II are associated in the blood with specific binding proteins (BPs), forming complexes that elute in gel filtration with estimated mol wt around 40 and 150 kD. The latter appears to be under GH control. Five molecular forms of BP (41.

Isolation from human cerebrospinal fluid of a new insulin-like growth factor-binding protein with a selective affinity for IGF-II.

In biological fluids IGF-I and IGF-II are bound to specific, high-affinity binding protein (BPs). Two human BPs have been isolated, one from serum, which is GH-dependent, the other from amniotic fluid (AF BP), and their cDNAs have recently been cloned. We report here the isolation of another, new species from cerebrospinal fluid (CSF) where this BP predominates.

Purified preparations of the amniotic fluid-derived insulin-like growth factor-binding protein contain multimeric forms that are biologically active.

The insulin-like growth factors (IGFs) appear to be secreted into interstitial fluids by many cell types, along with specific, high affinity binding proteins (IGF-BPs). These proteins, therefore, have the potential to bind IGF-I and -II and modify their ability to interact with specific cell surface receptors In these studies we report the detection of high mol wt, multimeric forms of one form of IGF-BP that has been purified from human amniotic fluid. The multimeric forms, which are either not or barely detectable in native amniotic fluid, are the result of intermolecular disulfide bond formation and can be reduced to a monomeric form by exposure to dithiothreitol.

Production of insulin-like growth factors and their binding proteins by rabbit articular chondrocytes: relationships with cell multiplication.

Articular chondrocytes from 2- to 3-month-old rabbits were cultured in serum-free medium supplemented with fibroblast growth factor. The effects were studied of GH, insulin-like growth factors (IGFs), and insulin on the production of IGF-I, IGF-II, and their binding proteins (BPs) and on cell multiplication. In the control culture medium, IGF-I levels were about one fifth those of IGF-II.

Insulin-like growth factor (IGF) and IGF-binding proteins: comparison of human serum and lymph.

The extent to which the association between insulin-like growth factors (IGFs) and their specific binding proteins (BPs) prevents their crossing the capillary barrier was studied by comparing their distribution in serum with that in samples of lymph collected from the lower leg of five subjects undergoing radiographical investigation of the lymphatic system. The IGF concentrations in lymph were 10-30% of the corresponding serum levels, and in each subject the ratios of IGF-I and IGF-II in the lymph to those in the serum were similar. Western blot analysis of the BPs revealed that the five molecular forms identified in serum also were present in lymph, but in significantly smaller quantities.

Heterogeneity of insulin-like growth factor binding proteins between structure and affinity. 2. Forms released by human and rat liver in culture.

Since the liver is considered to be the major source both of circulating insulin-like growth factors (IGFs) and of their specific binding proteins (BPs), human and rat liver explants were cultured in serum-free medium with a view to characterizing the binding proteins released into the medium and to comparing them with serum binding proteins. In the culture media, as in the serum, IGFs are associated with their binding proteins in the form of complexes. In gel filtration experiments the liver IGF-BP complexes eluted as a single, homogeneous peak with a relative molecular mass of about 40,000, which is similar to that of the 'small' complex of serum.

Heterogeneity of insulin-like growth factor binding proteins and relationships between structure and affinity. 1. Circulating forms in man.

Circulating insulin-like growth factors (IGFs) are bound to specific, high-affinity binding proteins (BPs), and form complexes with relative molecular masses of about 150,000 ('large' complex) and 40,000 ('small' complex). The large complex appears to be under growth-hormone control and its proportions vary with those of the IGFs. Molecular heterogeneity among the binding proteins was revealed by polyacrylamide gel electrophoresis (SDS-PAGE) of serum in which they were cross-linked to 125I-labelled IGF I or II.

Identification of an insulin-like growth factor-binding protein in human cerebrospinal fluid with a selective affinity for IGF-II.

Human cerebrospinal fluid (CSF) has been found to contain several different molecular forms of IGF-specific binding proteins (BPs). Qualitatively, they are similar to those present in serum, although their relative proportions are very different, as well as to those present in the culture media of brain tissue from which these BPs presumably arise. One particular form of BP is predominant in CSF.

Analysis of serum insulin-like growth factor binding proteins using western blotting: use of the method for titration of the binding proteins and competitive binding studies.

A nitrocellulose gel transfer technique has been adapted to study the insulin-like growth factor (IGF) binding proteins of human serum. Normal and hypopituitary sera were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by electroblotting to nitrocellulose or nylon membrane. Nonidet-P40 (3%) and Tween 20 (0.

Somatomedin (insulin-like growth factors)-binding proteins. Molecular forms and regulation.

The insulin-like growth factor (IGF)-binding proteins present in the human serum and various biological media have been characterized by several methods: gel filtration, sucrose gradient sedimentation, polyacrylamide gel electrophoresis and chromatofocusing. Several forms have been identified with molecular weights of approximately 42,000, 39,000, 34,000, 30,000 and 24,000 daltons. Results of competitive binding studies suggest that the different forms of binding proteins have different affinities for IGF-I and IGF-II.

Evidence for production by the liver of two IGF binding proteins with similar molecular weights but different affinities for IGF I and IGF II. Their relations with serum and cerebrospinal fluid IGF binding proteins.

Studies of the competitive binding of IGF I and IGF II and 125I-labelled IGF I and IGF II to the specific binding proteins (BPs) produced by the liver in culture suggest that two BPs exist, one with a selective affinity for IGF I and the other with a selective affinity for IGF II. The ratio of the former BP to the latter appeared to be higher in the culture medium of young rat livers and of fetal human livers than that in the culture medium of adult human livers. The two BPs form complexes with their IGFs with the same apparent molecular weight of approximately 40K.

[Biosynthesis and hormonal regulation of IGF (insulin-like growth factors, or somatomedins). Experimental and clinical studies (author's transl)].

Rat liver explants in culture release into the culture medium IGF and their carrier which form a complex with an apparent molecular weight of similar to or approximately 40,000. With gel filtration in acetic acid the IGF are separated from their carrier and each can then be measured by radioligand assay. In terms of their hormonal control "in vitro", GH, insulin and cortisol have an independent action on each.

Transcription in vitro of adenovirus-2 DNA by RNA polymerases class C purified from uninfected and adenovirus-infected HeLa cells.

DNA-dependent RNA polymerase class C (or III) has been solubilized from either uninfected or adenovirus-2-infected HeLa cells and purified by chromatography on phosphocellulose, DNA-cellulose, CM-Sephadex and DEAE-Sephadex. The last column separated the enzyme into three forms CI, CII and CIII, which were completely free of RNA polymerases class A and B and of DNase and RNase. The total and the relative amount of these different enzyme C forms did not vary whether purified from uninfected or infected cells.

Animal DNA-dependent RNA polymerases. Partial purification and properties of three classes of RNA polymerases from uninfected and adenovirus-infected HeLa cells.

DNA-dependent RNA polymerase was solubilized from normal and adenovirus-2 infected HeLa cells. Multiple peaks of enzyme activity were separated by DEAE-Sephadex chromatography. In addition to class A and B enzyme activities (respectively insensitive and sensitive to inhibition by 10 nM alpha-amanitin), three peaks of class C enzyme activity were found which are sensitive to inhibition by alpha-amanitin only at much higher concentrations (0.