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J Sundelin

Publications and source records attributed to J Sundelin.

At least 37 records · Page 2Linked to original sources
PubMed1986

Increased levels of several retinoid binding proteins resulting from retinoic acid-induced differentiation of F9 cells.

The embryonal carcinoma cell line F9 is known to differentiate when exposed to retinoic acid. We have examined the quantities of two intracellular retinoid-binding proteins in undifferentiated and differentiated F9 cells. The existence of a cell surface receptor that recognizes the plasma retinol-binding protein was also explored. It was shown that undifferentiated F9 cells contain low concentrations of the two retinoid-binding proteins. The cellular retinoic acid-binding protein was present in approximately 3-fold molar excess over the cellular retinol-binding protein. Upon culture in the presence of retinoic acid, F9 cells display elevated concentrations of both cellular retinol-binding protein and cellular retinoic acid-binding protein. Since the levels of beta 2-microglobulin, a marker of the differentiated state with no known involvement in the metabolism of vitamin A, increased in parallel with the retinoid-binding proteins, it seems unlikely that retinoic acid selectively increased the levels of the two retinoid-binding proteins. The differentiated, in contrast to the undifferentiated cells, can accumulate retinol from plasma retinol-binding protein and display a cell surface receptor for this protein. Despite the fact that retinoic acid-induced differentiation of F9 cells promotes increased levels of several proteins involved in the normal metabolism of vitamin A, no evidence was obtained to suggest that the cells were dependent on retinoids to maintain their differentiated state.

Animals↗
PubMed1985

Characterization of the rat retinol-binding protein gene and its comparison to the three-dimensional structure of the protein.

Rat genomic DNA fragments bearing the retinol-binding protein (RBP) gene have been isolated and characterized. The gene spans 6.9 kilobases and contains six exons. The five intervening sequences range in size from 78 base pairs to 4.4 kilobase pairs with the first interrupting the 5' untranslated region. A comparison of the gene organization with the three-dimensional structure of RBP reveals that all translated exon transcripts closely correspond to discrete tertiary structural elements. Residues of the protein involved in the retinol binding are encoded by three separate exons. It has been proposed that the two regions displaying internal homology in the human RBP, both at the primary and tertiary structure levels, arose by a partial ancestral gene duplication. If such an event were involved, evidence for it at the nucleotide sequence and exon-intron organization levels has been obscured.

Animals↗
PubMed1985

Cellular retinoid binding proteins.

The cellular retinol-binding protein (CRBP) and the cellular retinoic acid binding protein (CRABP) have similar physicochemical characteristics. The amino acid sequences of rat CRBP and bovine CRABP have been elucidated and they display 40% sequence identity. Both protein sequences appear to be evolutionarily highly conserved. The amino acid sequence of human CRBP, deduced from a cDNA-clone, is 96% identical to the rat CRBP sequence. CRBP and CRABP are members of a protein family, all members of which may bind hydrophobic ligands and interact with membrane components. All members of the protein family are probably related in tertiary structure and might interact with membrane components through two regions with a high probability for alpha-helix. The tissue distribution of CRBP and CRABP, together with their relation to lipid transporting proteins suggests that CRBP and CRABP are cellular transporting proteins for retinol and retinoic acid, respectively.

Amino Acid Sequence↗
PubMed1985

Amino acid sequence of an egg-lysin protein from abalone spermatozoa that solubilizes the vitelline layer.

Spermatozoa of the California red abalone (Haliotis rufescens; Phylum Mollusca, order Archeogastropoda) possess an acrosomal protein that dissolves the egg vitelline layer during fertilization. Evidence strongly suggests that the dissolution mechanism is a stoichiometric, nonenzymatic process that depends on the hydrophobic nature of the sperm protein which should therefore be termed an egg-lysin. Here we report the complete amino acid sequence of this unique protein. Peptides obtained by cyanogen bromide cleavage and trypsin and V8 protease digestions were isolated and subjected to automated Edman degradation. Seven unique CNBr fragments accounted for the intact lysin and the proteolytically derived peptides were used to establish the order of these fragments. The protein is composed of 134 amino acids and contains 36 charged amino acids. The majority of these occur at distances of 2 or 3 residues from each other. A stretch of 41 amino acids contains 10 positively charged amino acids and no negatively charged residue. Model building experiments demonstrated that the charged residues that may occur in alpha-helical regions of the protein would occupy one-half of the circumference of such helices. The other half would display predominantly hydrophobic residues. This arrangement of the charged and hydrophobic residues may account for the biological properties of the lysin.

Amino Acid Sequence↗
PubMed1985

Cloning and sequencing of a full length cDNA corresponding to human cellular retinol-binding protein.

We have isolated and sequenced a cDNA clone corresponding to the human cellular retinol-binding protein (CRBP). The deduced amino acid sequence, which encompasses 134 amino acid residues, shows significant homology with several low molecular weight proteins which bind hydrophobic ligands. No homology to the plasma retinol-binding protein was observed. Southern and Northern blot analyses suggest that the CRBP gene is present in a single copy in the haploid genome and that it is transcribed in a single mRNA species.

Amino Acid Sequence↗
PubMed1985

The primary structure of bovine cellular retinoic acid-binding protein.

The complete amino acid sequence of bovine adrenal gland cellular retinoic acid-binding protein (CRABP) has been determined. The primary structure was established by analyses of cyanogen bromide fragments and peptides obtained by trypsin and Staphylococcus aureus protease digestions. The polypeptide chain of bovine CRABP comprises 136 amino acid residues. From partial sequence information, CRABP has been shown to be homologous to cellular retinol-binding protein, myelin protein P2, and the fatty acid-binding Z-protein. A comparison of the complete amino acid sequences of the members of this protein family, which also includes the rat intestinal fatty acid-binding protein, shows that CRABP is more similar to cellular retinol-binding protein and protein P2 than to the fatty acid-binding proteins. All five proteins are very similar in their NH2-terminal regions, suggesting that this part is important for a property common to the members of this protein family. This is the first report of a complete amino acid sequence of a CRABP.

Adrenal Glands↗
PubMed1985

Amino acid sequence homologies between rabbit, rat, and human serum retinol-binding proteins.

The main transporting protein for vitamin A in rabbit serum, the retinol-binding protein (RBP), was isolated and its amino acid sequence determined. Rabbit RBP was found to be highly homologous to human RBP, whose amino acid sequence was elucidated earlier, and to rat RBP. The rat RBP sequence was obtained by combining information deduced from the nucleotide sequences of two overlapping cDNA clones with the NH2-terminal sequence of the isolated protein determined by automated Edman degradation. The identity between the three proteins is approximately 90%. The high degree of homology between RBP molecules from different species is probably explained by the fact that RBP participates in at least three types of molecular interactions: in the binding of prealbumin, in the interaction with retinol, and in the recognition of a specific cell surface receptor. All these interactions should lead to a conservation of RBP structure. The amino acid differences between rabbit, rat, and human RBP are discussed in light of the recent elucidation of the three-dimensional structure of human RBP. Hybridization of a probe isolated from a rat RBP cDNA clone to restriction enzyme-digested genomic DNA from rat and mouse suggests that RBP is encoded by a single gene.

Amino Acid Sequence↗
PubMed1985

The primary structure of rabbit and rat prealbumin and a comparison with the tertiary structure of human prealbumin.

The primary structures of rabbit and rat prealbumin have been determined. The amino acid sequence of rabbit prealbumin was determined by analyses of peptides obtained by trypsin and Staphylococcus aureus protease digestions. The rat prealbumin sequence was deduced by analyses of tryptic peptides as well as by nucleotide sequencing of cDNA clones. Both amino acid sequences contain 127 amino acid residues, the same as human prealbumin. Pairwise comparisons show that the three sequences are more than 80% identical. All three prealbumins were found to display significant sequence homology with human thyroxine-binding globulin. A comparison of the primary structures of the prealbumins with the tertiary structure of human prealbumin shows that amino acid replacements are preferentially located at the surface of the molecule and in the loops connecting the beta-strands. The locations of the replacements are discussed as regards the different molecular interactions in which prealbumin is involved.

Amino Acid Sequence↗
PubMed1985

The primary structure of rat liver cellular retinol-binding protein.

The complete amino acid sequence of a cellular retinol-binding protein (CRBP) has been determined for the first time. The primary structure of rat liver CRBP was elucidated by analyses of cyanogen bromide fragments and peptides obtained by tryptic and thermolytic digestions. The single polypeptide chain of rat CRBP consists of 134 amino acid residues. Under reducing conditions, CRBP exists as a monomer, but, in the absence of reducing agents, dimers and multimers of the protein emerge. This is explained by the observation that CRBP contains 3 cysteines, one of which seems to be highly reactive. Whether CRBP contains a disulfide bond is not yet established. The present data extend the previously described homology between CRBP and a family of low molecular weight proteins, all members of which may bind hydrophobic ligands. Since some of these proteins apparently display intracellular transport functions, a similar role for CRBP is envisaged.

Amino Acid Sequence↗
PubMed1984

Cellular retinol-binding protein. Quantitation and distribution.

The distribution of cellular retinol-binding protein was localized in three tissues involved in the transport of vitamin A using the peroxidase-antiperoxidase technique. In addition, a sensitive radioimmunoassay was developed to quantitate cellular retinol-binding protein in various tissues. In liver, the protein was found in the hepatocytes and in the perisinusoidal fat-storing cells. The columnar epithelial cells of the jejunum and the cells of the proximal tubuli also exhibit high concentrations of cellular retinol-binding protein. Estimations of the content of the protein in various tissues from normal and retinol-deficient rats showed that the retinol status did not affect the tissue levels or the subcellular distribution. The appearance of high amounts of this protein in cells involved in the dietary uptake, storage, mobilization, and resorption of vitamin A suggest that one function of the cellular retinol-binding protein is to act as a vehicle in the intracellular transport of retinol through these organs.

Amino Acid Sequence↗
PubMed1984

Crystallization of and preliminary X-ray data for the plasma retinol-binding protein.

Crystals of the human and rabbit plasma retinol-binding proteins have been grown from solutions of polyethylene glycol 6000 and CdCl2. Two crystal forms have been observed for the human protein, while the rabbit protein has only crystallized in one form which is isomorphous with one of the human serum retinol-binding protein crystals. The crystals differ in their morphologies, but are both in space group P212121 and have similar unit cell sizes (a = 45.9, b = 53.3, c = 72.0 A and a = 45.7, b = 48.7, and c = 76.5 A). The crystals diffract to approximately 2.0 A resolution. In both cases there is 1 molecule/asymmetric unit.

Crystallization↗
PubMed1984

The three-dimensional structure of retinol-binding protein.

The complex of retinol with its carrier protein, retinol-binding protein (RBP) has been crystallized and its three-dimensional structure determined using X-ray crystallography. Its most striking feature is an eight-stranded up-and-down beta barrel core that completely encapsulates the retinol molecule. The retinol molecule lies along the axis of the barrel with the beta-ionone ring innermost and the tip of the isoprene tail close to the surface.

Animals↗
PubMed1983

Recovery of proteins on a milligram scale from polyacrylamide electrophoresis gels, exemplified by purification of a retinol-binding protein.

An apparatus suitable for the recovery of proteins from polyacrylamide gels on a milligram scale by displacement electrophoresis (isotachophoresis) is described along with a buffer system that is suitable for this purpose with most proteins. The technique is illustrated by the recovery of a protein from a 15% polyacrylamide gel. The recovery was almost quantitative and the eluted protein showed little contamination upon quantitative amino acid analysis and automatic Edman degradation.

Amino Acid Sequence↗
PubMed1983

Structure and tissue distribution of some retinoid-binding proteins.

Vitamin A has, apart from its function in the visual pigments, general effects on several organs. Early signs of vitamin A deficiency include keratinization of epithelia and hyperkeratosis of the skin. To elucidate a generalized function for vitamin A, we have taken the approach of tracing the vitamin from its storage site in the liver via its blood transport by the retinol-binding protein (RBP) to its uptake by susceptible cells. We have also examined the intracellular occurrence of vitamin A as regards its binding to specific receptor proteins. Here we summarize data on the amino acid sequences of several vitamin A-binding proteins. The finding that CRBP and CRABP, the two intracellular proteins, are homologous to each other, to a myelin protein, and to a fatty acid-binding protein may shed light on the functions of these proteins. Retinoic acid, which binds to CRABP but not CRBP, induces differentiation of teratocarcinoma cells. This is accompanied by a lowering of the CRABP concentration, an increase of the CRBP level, and an increase in the uptake of retinol from RBP. The epidermis contains both CRBP and CRABP, and their distributions are rather similar. However, in contrast to CRBP, CRABP is most abundant in cells lining the hair follicles. CRBP occurs in greatest relative amounts in the outer layers of the epidermis. Since techniques have been developed to measure CRBP and CRABP, normal and disease-affected skin may now be explored as to quantity and cellular distribution of the retinoid-binding proteins.

Amino Acid Sequence↗
PubMed1982

The cell attachment domain of fibronectin. Determination of the primary structure.

The complete amino acid sequence of the cell attachment domain of human plasma fibronectin (Pierschbacher, M. D., Hayman, E. G., and Ruoslahti, E. (1981) Cell 26, 259-267) has been determined by automated sequential degradation of a peptic fragment comprising this region and of peptides derived from this fragment by digestion with thermolysin, staphylococcal V8 protease, cyanogen bromide cleavage, and partial acid hydrolysis. The fragment contains 108 residues with isoleucine and methionine as the NH2- and carboxyl-terminal amino acids, respectively. No cysteines are present. The calculated molecular weight of the cell attachment fragment, based on the amino acid sequence, is 11,482, which is in good agreement with the molecular weight estimated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and ultracentrifugation. There are no homologies in this fragment with other published sequences. The implications of the structure of the cell attachment fragment to the molecular mechanism of cell-fibronectin interaction are discussed.

Amino Acid Sequence↗
PubMed1982

Alpha chain of HLA-DR transplantation antigens is a member of the same protein superfamily as the immunoglobulins.

Four cDNA clones, pDR-alpha-1, pDR-alpha-2, pDR-alpha-3 and pDR-alpha-4, corresponding to the alpha chain of HLA-DR antigens, have been sequenced. Restriction maps and sequences suggest that all clones are identical apart from a single-base substitution present in pDR-alpha-1. Amino acid sequence data, together with the nucleotide sequence data, allowed the complete amino acid sequence to be predicted. The alpha chain is composed of 229 amino acids, of which 191 are exposed on the outside of the plasma membrane. The membrane-embedded portion of the chain consists of 23 hydrophobic amino acids. The succeeding 15 amino acids form the cytoplasmically localized hydrophilic tail. The extracellular portion, with carbohydrate moieties linked to Asn78 and Asn118, seems to be organized into two domains. The second domain, which contains the only disulfide bond of the alpha chain, displays amino acid sequence homology to immunoglobulin constant regions, to the second domain of the beta chain of a class II antigen, to the third domain of heavy chains of class I antigens and to beta 2-microglobulin. Thus the subunits of immunoglobulins, class I antigens and class II antigens are related evolutionarily.

Amino Acid Sequence↗
PubMed1982

Isolation and identification of a cDNA clone corresponding to an HLA-DR antigen beta chain.

The HLA-D locus in the major histocompatibility complex controls the expression of the genetically polymorphic HLA-DR antigens. mRNA coding for the beta chains of these antigens was partially purified from the human lymphoblastoid cell line Raji. The mRNA was copied into double-stranded cDNA and cloned in Escherichia coli. One clone, pDR-beta-1, obtained by hybrid selection, carries a 1070-base-pair insert comprising all of the coding region except the signal sequence and a substantial portion of the untranslated region. To identify pDR-beta-1, highly purified HLA-DR antigen beta chains derived from Raji cells were subjected to NH2-terminal amino acid sequence determination. This sequence displayed extensive homology with that deduced from the nucleotide sequence at the 5' end of the pDR-beta-1 coding region. Taken together, the amino acid and nucleotide sequences strongly argue in favor of Raji cells containing at least two beta-chain loci.

Amino Acid Sequence↗