scholarly journals The amino acid sequences of the myelin-associated glycoproteins: homology to the immunoglobulin gene superfamily

1987 ◽  
Vol 104 (4) ◽  
pp. 957-965 ◽  
Author(s):  
JL Salzer ◽  
WP Holmes ◽  
DR Colman
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Growth Factor Receptor ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Immunoglobulin Gene ◽  
Expression Library ◽  
Extracellular Region ◽  
Immunoglobulin Gene Superfamily ◽  
Membrane Spanning

The myelin associated glycoproteins (MAG) are integral plasma membrane proteins which are found in oligodendrocytes and Schwann cells and are believed to mediate the axonal-glial interactions of myelination. In this paper we demonstrate the existence in central nervous system myelin of two MAG polypeptides with Mrs of 67,000 and 72,000 that we have designated small MAG (S-MAG) and large MAG (L-MAG), respectively. The complete amino acid sequence of L-MAG and a partial amino acid sequence of S-MAG have been deduced from the nucleotide sequences of corresponding cDNA clones isolated from a lambda gt11 rat brain expression library. Based on their amino acid sequences, we predict that both proteins have an identical membrane spanning segment and a large extracellular domain. The putative extracellular region contains an Arg-Gly-Asp sequence that may be involved in the interaction of these proteins with the axon. The extracellular portion of L-MAG also contains five segments of internal homology that resemble immunoglobulin domains, and are strikingly homologous to similar domains of the neural cell adhesion molecule and other members of the immunoglobulin gene superfamily. In addition, the two MAG proteins differ in the extent of their cytoplasmically disposed segments and appear to be the products of alternatively spliced mRNAs. Of considerable interest is the finding that the cytoplasmic domain of L-MAG, but not of S-MAG, contains an amino acid sequence that resembles the autophosphorylation site of the epidermal growth factor receptor.

scholarly journals Structural features of the low-molecular-mass human salivary mucin

1992 ◽  
Vol 287 (2) ◽  
pp. 639-643 ◽  
Author(s):  
M S Reddy ◽  
L A Bobek ◽  
G G Haraszthy ◽  
A R Biesbrock ◽  
M J Levine
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Mass ◽  
Gel Filtration ◽  
Structural Features ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Expression Library ◽  
Mrna Species ◽  
Salivary Mucin

The low-molecular-mass human salivary mucin has at least two isoforms, MG2a and MG2b, that differ primarily in their sialic acid and fucose content. In this study, we characterize further these isoforms, particularly their peptide moieties. Trypsin digests of MG2a and MG2b yielded high- and low-molecular-mass glycopeptides following gel filtration on Sephacryl S-300. The larger glycopeptides from MG2a and MG2b had similar amino acid compositions and identical N-terminal sequences, suggesting common structural features between their peptides. An oligonucleotide probe generated from the amino acid sequence of the smaller glycopeptide from MG2a was employed in Northern-blot analysis. This probe specifically hybridized to two mRNA species from human submandibular and sublingual glands. A cDNA clone selected from a human submandibular gland cDNA expression library with antibody generated against deglycosylated MG2a also hybridized to these two mRNA species. In both cases, the larger mRNA was polydisperse, and the hybridization signal was more intense in the sublingual gland. In addition, the N-terminal amino acid sequence of the larger glycopeptide was found to be part of one of the selected MG2 cDNA clones.

scholarly journals Purification, characterization and cDNA cloning of human lung surfactant protein D

1992 ◽  
Vol 284 (3) ◽  
pp. 795-802 ◽  
Author(s):  
J Lu ◽  
A C Willis ◽  
K B M Reid
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Mass ◽  
Human Lung ◽  
Solid Phase ◽  
Surfactant Protein ◽  
Amino Acid Sequences ◽  
Surfactant Protein D ◽  
Cdna Clones ◽  
Oligonucleotide Probes

Human pulmonary surfactant protein D (SP-D) was identified in lung lavage by its similarity to rat SP-D in both its molecular mass and its Ca(2+)-dependent-binding affinity for maltose [Persson, Chang & Crouch (1990) J. Biol. Chem. 265, 5755-5760]. For structural studies, human SP-D was isolated from amniotic fluid by affinity chromatography on maltose-Sepharose followed by f.p.l.c. on Superose 6, which showed it to have a molecular mass of approx. 620 kDa in non-dissociating conditions. On SDS/PAGE the human SP-D behaved as a single band of 150 kDa or 43 kDa in non-reducing or reducing conditions respectively. The presence of a high concentration of glycine (22%), hydroxyproline and hydroxylysine in the amino acid composition of human SP-D indicated that it contained collagen-like structure. Collagenase digestion yielded a 20 kDa collagenase-resistant globular fragment which retained affinity for maltose. Use of maltosyl-BSA as a neoglycoprotein ligand in a solid-phase binding assay showed that human SP-D has a similar carbohydrate-binding specificity to rat SP-D, but a clearly distinct specificity from that of other lectins, such as conglutinin, for a range of simple saccharides. Amino acid sequence analysis established the presence of collagen-like Gly-Xaa-Yaa triplets in human SP-D and also provided sequence data from the globular region of the molecule which was used in the synthesis of oligonucleotide probes. Screening of a human lung cDNA library with the oligonucleotide probes, and also with rabbit anti-(human SP-D), allowed the isolation of two cDNA clones which overlap to give the full coding sequence of human SP-D. The derived amino acid sequence indicates that the mature human SP-D polypeptide chain is 355 residues long, having a short non-collagen-like N-terminal section of 25 residues, followed by a collagen-like region of 177 residues and a C-terminal C-type lectin domain of 153 residues. Comparison of the human SP-D and bovine serum conglutinin amino acid sequences indicated that they showed 66% identity despite their marked differences in carbohydrate specificity.

cDNA cloning of transcription factor E4TF1 subunits with Ets and notch motifs

1993 ◽  
Vol 13 (3) ◽  
pp. 1385-1391
Author(s):  
H Watanabe ◽  
J Sawada ◽  
K Yano ◽  
K Yamaguchi ◽  
M Goto ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Amino Acid ◽  
Dna Binding ◽  
Amino Acid Sequence ◽  
Binding Activity ◽  
Amino Acid Sequences ◽  
Predicted Amino Acid Sequence ◽  
Cdna Clones ◽  
Dna Binding Activity

E4TF1 was originally identified as one of the transcription factors responsible for adenovirus E4 gene transcription. It is composed of two subunits, a DNA binding protein with a molecular mass of 60 kDa and a 53-kDa transcription-activating protein. Heterodimerization of these two subunits is essential for the protein to function as a transcription factor. In this study, we identified a new E4TF1 subunit, designated E4TF1-47, which has no DNA binding activity but can associate with E4TF1-60. We then cloned the cDNAs for each of the E4TF1 subunits. E4TF1 was purified, and the partial amino acid sequence of each subunit was determined. The predicted amino acid sequence of each cDNA clone revealed that E4TF1-60 had an ETS domain, which is a DNA binding domain common to ets-related transcription factors. E4TF1-53 had four tandemly repeated notch-ankyrin motifs. The putative cDNA of E4TF1-47 coded almost the same amino acid sequences as E4TF1-53. Three hundred and thirty-two amino acids of the N termini of E4TF1-47 and -53 were identical except for one amino acid insertion in E4TF1-53, and they differ from each other at the C terminus. These three recombinant cDNA clones were expressed in Escherichia coli, and the proteins behaved in the same manner as purified proteins in a gel retardation assay. Nucleotide and predicted amino acid sequences were highly homologous to GABP-alpha and -beta, which is further supported by the observation that GABP-specific antibody can recognize human E4TF1.

scholarly journals Molecular cloning and deduced amino acid sequences of the α- and β- subunits of mammalian NAD+-isocitrate dehydrogenase

1995 ◽  
Vol 310 (3) ◽  
pp. 917-922 ◽  
Author(s):  
B J Nichols ◽  
A C F Perry ◽  
L Hall ◽  
R M Denton
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Isocitrate Dehydrogenase ◽  
Sequence Data ◽  
Amino Acid Sequences ◽  
Beta Subunit ◽  
Peptide Sequence ◽  
Alpha Subunit ◽  
Cdna Clones ◽  
Oligonucleotide Primers

A 153 bp fragment of the cDNA encoding the beta-subunit of pig heart NAD(+)-isocitrate dehydrogenase (NAD(+)-ICDH) was specifically amplified by PCR, using redundant oligonucleotide primers based on partial peptide sequence data [Huang and Colman (1990) Biochemistry 29, 8266-8273]. This PCR fragment was then used as a probe to isolate cDNA clones encoding the complete mature form of the beta-subunit from a monkey testis cDNA library. Examination of the deduced amino acid sequence of the monkey subunit and the partial sequence of the pig heart enzyme revealed a high level of sequence conservation. In addition, 3 overlapping fragments of the cDNA for the alpha-subunit of monkey NAD(+)-ICDH were amplified using oligonucleotide primers derived from the cDNA sequence of a subunit of bovine NAD(+)-ICDH (EMBL accession no: U07980). These cDNA fragments allow deduction of the amino acid sequence of the alpha-subunit. Since the gamma-subunit of monkey NAD(+)-ICDH has already been cloned [Nichols, Hall, Perry and Denton (1993) Biochem. J. 295, 347-350], a deduced amino acid sequence is now available for all three subunits of mammalian NAD(+)-ICDH. Interrelationships between these subunits are discussed and they are compared with the two subunits of yeast NAD(+)-ICDH and Escherichia coli NADP(+)-ICDH.

scholarly journals Dictyostelium discoideum myosin: isolation and characterization of cDNAs encoding the essential light chain.

1988 ◽  
Vol 8 (2) ◽  
pp. 794-801 ◽  
Author(s):  
R L Chisholm ◽  
A M Rushforth ◽  
R S Pollenz ◽  
E R Kuczmarski ◽  
S R Tafuri
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dictyostelium Discoideum ◽  
Light Chain ◽  
Single Gene ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Expression Library ◽  
Essential Light Chain ◽  
Isolation And Characterization

We used an antibody specific for Dictyostelium discoideum myosin to screen a lambda gt11 cDNA expression library to obtain cDNA clones which encode the Dictyostelium essential myosin light chain (EMLC). The amino acid sequence predicted from the sequence of the cDNA clone showed 31.5% identity with the amino acid sequence of the chicken EMLC. Comparisons of the Dictyostelium EMLC, a nonmuscle cell type, with EMLC sequences from similar MLCs of skeletal- and smooth-muscle origin, showed distinct regions of homology. Much of the observed homology was localized to regions corresponding to consensus Ca2+-binding of E-F hand domains. Southern blot analysis suggested that the Dictyostelium genome contains a single gene encoding the EMLC. Examination of the pattern of EMLC mRNA expression showed that a significant increase in EMLC message levels occurred during the first few hours of development, coinciding with increased actin expression and immediately preceding the period of maximal chemotactic activity.

scholarly journals cDNA cloning of transcription factor E4TF1 subunits with Ets and notch motifs.

1993 ◽  
Vol 13 (3) ◽  
pp. 1385-1391 ◽  
Author(s):  
H Watanabe ◽  
J Sawada ◽  
K Yano ◽  
K Yamaguchi ◽  
M Goto ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Amino Acid ◽  
Dna Binding ◽  
Amino Acid Sequence ◽  
Binding Activity ◽  
Amino Acid Sequences ◽  
Predicted Amino Acid Sequence ◽  
Cdna Clones ◽  
Dna Binding Activity

E4TF1 was originally identified as one of the transcription factors responsible for adenovirus E4 gene transcription. It is composed of two subunits, a DNA binding protein with a molecular mass of 60 kDa and a 53-kDa transcription-activating protein. Heterodimerization of these two subunits is essential for the protein to function as a transcription factor. In this study, we identified a new E4TF1 subunit, designated E4TF1-47, which has no DNA binding activity but can associate with E4TF1-60. We then cloned the cDNAs for each of the E4TF1 subunits. E4TF1 was purified, and the partial amino acid sequence of each subunit was determined. The predicted amino acid sequence of each cDNA clone revealed that E4TF1-60 had an ETS domain, which is a DNA binding domain common to ets-related transcription factors. E4TF1-53 had four tandemly repeated notch-ankyrin motifs. The putative cDNA of E4TF1-47 coded almost the same amino acid sequences as E4TF1-53. Three hundred and thirty-two amino acids of the N termini of E4TF1-47 and -53 were identical except for one amino acid insertion in E4TF1-53, and they differ from each other at the C terminus. These three recombinant cDNA clones were expressed in Escherichia coli, and the proteins behaved in the same manner as purified proteins in a gel retardation assay. Nucleotide and predicted amino acid sequences were highly homologous to GABP-alpha and -beta, which is further supported by the observation that GABP-specific antibody can recognize human E4TF1.

Dictyostelium discoideum myosin: isolation and characterization of cDNAs encoding the essential light chain

1988 ◽  
Vol 8 (2) ◽  
pp. 794-801
Author(s):  
R L Chisholm ◽  
A M Rushforth ◽  
R S Pollenz ◽  
E R Kuczmarski ◽  
S R Tafuri
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dictyostelium Discoideum ◽  
Light Chain ◽  
Single Gene ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Expression Library ◽  
Essential Light Chain ◽  
Isolation And Characterization

We used an antibody specific for Dictyostelium discoideum myosin to screen a lambda gt11 cDNA expression library to obtain cDNA clones which encode the Dictyostelium essential myosin light chain (EMLC). The amino acid sequence predicted from the sequence of the cDNA clone showed 31.5% identity with the amino acid sequence of the chicken EMLC. Comparisons of the Dictyostelium EMLC, a nonmuscle cell type, with EMLC sequences from similar MLCs of skeletal- and smooth-muscle origin, showed distinct regions of homology. Much of the observed homology was localized to regions corresponding to consensus Ca2+-binding of E-F hand domains. Southern blot analysis suggested that the Dictyostelium genome contains a single gene encoding the EMLC. Examination of the pattern of EMLC mRNA expression showed that a significant increase in EMLC message levels occurred during the first few hours of development, coinciding with increased actin expression and immediately preceding the period of maximal chemotactic activity.

scholarly journals Isolation and sequence analysis of a cDNA encoding rat liver α-l-fucosidase

1989 ◽  
Vol 264 (3) ◽  
pp. 695-701 ◽  
Author(s):  
K J Fisher ◽  
N N Aronson
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Signal Peptide ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Amino Acid Residues ◽  
Expression Library ◽  
Cdna Insert ◽  
Untranslated Sequence ◽  
N Terminus

cDNA clones for alpha-L-fucosidase were isolated from a rat liver lambda gt11 expression library by using both monospecific polyclonal antibodies against the affinity-purified enzyme and biotinylated rat liver fucosidase cDNA sequences as probes. The largest clone, lambda FC9, contained a 1522 bp full-length cDNA insert (FC9) that encoded the 434-amino acid-residue subunit (Mr 50439) of rat liver alpha-L-fucosidase. A putative signal peptide 28 amino acid residues in length preceded the sequence for the mature protein. In addition, FC9 specified for 11 nucleotide residues of 5′ untranslated sequence, 78 nucleotide residues of 3′ untranslated sequence and a poly(A) tail. The deduced amino acid sequence from FC9 in conjunction with the experimentally determined N-terminus of the mature enzyme suggested that rat liver fucosidase did not contain a pro-segment. However, there was the possibility of limited N-terminal processing (one to five amino acid residues) having occurred after removal of the predicted signal peptide. Amino acid sequences deduced from FC9 were co-linear with amino acid sequences measured at the N-terminus of purified fucosidase and on two of its CNBr-cleavage peptides. An unusual aspect of rat liver alpha-L-fucosidase protein structure obtained from the FC9 data was its high content of tryptophan (6%). The coding sequence from FC9 showed 82% sequence identity with that from a previously reported incomplete human fucosidase sequence [O'Brien, Willems, Fukushima, de Wet, Darby, DiCioccio, Fowler & Shows, (1987) Enzyme 38, 45-53].

scholarly journals Cloning and sequence analysis of cDNAs encoding the α1, α2 and α3 chains of mouse collagen VI

1993 ◽  
Vol 291 (3) ◽  
pp. 787-792 ◽  
Author(s):  
R Z Zhang ◽  
T C Pan ◽  
R Timpl ◽  
M L Chu
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Untranslated Regions ◽  
Cdna Libraries ◽  
Cdna Clones ◽  
Collagen Vi ◽  
Central Segment ◽  
Glycosylation Sites ◽  
Key Features ◽  
Triple Helical Domain

cDNA clones encoding the alpha 1, alpha 2 and alpha 3 chains of mouse collagen VI have been isolated by screening cDNA libraries with the corresponding human probes. The composite cDNAs for the alpha 1, alpha 2, and alpha 3 chains are 2.5, 1.6 and 2.9 kb in size respectively. The alpha 1 and alpha 2 cDNAs encode the C-terminal portions of the chains as well as the entire 3′-untranslated regions, while the alpha 3 cDNAs encode a central segment of 959 amino acids flanking the triple-helical domain. The deduced amino acid sequences share 86-88% identity with the human counterparts and 67-73% identity with the chicken equivalents. Alignment of the deduced amino acid sequences of mouse, human and chicken collagens reveal that the key features of the protein, including the cysteine residues, imperfections in the Gly-Xaa-Xaa regions, Arg-Gly-Asp sequences and potential N-glycosylation sites, are mostly conserved.

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