scholarly journals Purification and characterization of avian glycolipid: beta-galactosyltransferases (GalT-4 and GalT-3): cloning and expression of truncated betaGalT-4.

1998 ◽  
Vol 45 (2) ◽  
pp. 451-467 ◽  
Author(s):  
S S Basu ◽  
S Dastgheib ◽  
S Ghosh ◽  
M Basu ◽  
P Kelly ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Fusion Protein ◽  
Catalytic Domain ◽  
Peptide Mapping ◽  
Cloning And Expression ◽  
Cdna Expression Library ◽  
Expression Library ◽  
Developmentally Regulated ◽  
Peptide Backbone ◽  
Protein Fingerprinting

Acidic glycolipid of ganglio-(containing sialic acid) and sialyl-lactofucosyl-type, SA-Lex (containing sialic acid and fucose) are developmentally regulated and appear to be ubiquitous on neuronal and cancer cell surfaces of animals. Two glycolipid: beta-galactosyltransferases, GalT-3 and GalT-4, were characterized in embryonic chicken brain (ECB). Based on substrate competition experiments, these two activities were believed to be due to expression of two gene products. A cDNA fragments (about 600 bp) encoding the catalytic domain of the GalT-4 (UDP-Gal:LcOse3Cer beta1,4galactosyltransferase) from ECB and human Colo-204 were isolated. These cDNAs were expressed as a soluble glutathione-S-transferase fusion protein (48 kDa) in Escherichia coli. Interactions between GlcNAc-, UDP-hexanolamine-, and alpha-lactalbumin were studied with the purified fusion protein (recombinant and truncated). Functionally it was similar to that of native GalT-4 purified (40000-fold) from 11-day-old ECB. GalT-3 (UDP-Gal:GM2beta1,3galactosyltransferase) was purified from 19-day-old ECB, and a polyclonal antibody was produced against the peptide backbone for immunoscreening of a lambdaZAP ECB cDNA expression library. Each of the GalT-3 peptides (62 and 65 kDa was analyzed by protein fingerprinting analysis indicating a similar peptide mapping pattern.

scholarly journals A novel 205-kilodalton testis-specific serine/threonine protein kinase associated with microtubules of the spermatid manchette.

1993 ◽  
Vol 13 (12) ◽  
pp. 7625-7635 ◽  
Author(s):  
P D Walden ◽  
N J Cowan
Keyword(s):  
Protein Complex ◽  
Catalytic Domain ◽  
Signal Transduction Pathway ◽  
Kinase Domain ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Expression Library ◽  
Serine Threonine Kinase ◽  
Expression Clone

To identify proteins which interact with and potentially modulate the function of microtubules during spermatogenesis, we prepared a total testis MAP (microtubule-associated protein) antiserum and used it to isolate cDNA clones from a mouse testis cDNA expression library. Antibodies affinity purified by using one expression clone recognized a 205-kDa protein, termed MAST205, which colocalizes with the spermatid manchette. Sequencing of full-length cDNA clones encoding MAST205 revealed it to be a novel serine/threonine kinase with a catalytic domain related to those of the A and C families. The testis-specific MAST205 RNA increases in abundance during prepuberal testis development, peaking at the spermatid stage. The microtubule-binding region of MAST205 occupies a central region of the molecule including the kinase domain and sequences C terminal to this domain. Binding of MAST205 to microtubules requires interaction with other MAPs, since it does not bind to MAP-free tubulin. A 75-kDa protein associated with immunoprecipitates of MAST205 from extracts of both whole testis and testis microtubules becomes phosphorylated in in vitro kinase assays. This 75-kDa substrate of the MAST205 kinase may form part of the MAST205 protein complex which binds microtubules. The MAST205 protein complex may function to link the signal transduction pathway with the organization of manchette microtubules.

scholarly journals Molecular cloning and expression of a unique rabbit osteoclastic phosphotyrosyl phosphatase

1996 ◽  
Vol 316 (2) ◽  
pp. 515-523 ◽  
Author(s):  
Li-Wha WU ◽  
David J. BAYLINK ◽  
K.-H. William LAU
Keyword(s):  
Fusion Protein ◽  
Catalytic Domain ◽  
Osteoclast Formation ◽  
Full Length ◽  
Cloning And Expression ◽  
Regulatory Role ◽  
Rabbit Brain ◽  
Extracellular Region ◽  
Tyrosyl Phosphorylation

Tyrosyl phosphorylation plays an important regulatory role in osteoclast formation and activity. Phosphotyrosyl phosphatases (PTPs), in addition to tyrosyl kinases, are key determinants of intracellular tyrosyl phosphorylation levels. To identify the PTP that might play an important regulatory role in osteoclasts, we sought to clone an osteoclast-specific PTP. A putative full-length clone encoding a unique PTP (referred to as PTP-oc) was isolated from a 10-day-old rabbit osteoclastic cDNA library and sequenced. A single open reading frame predicts a protein with 405 amino acid residues containing a putative extracellular domain, a single transmembrane region, and an intracellular portion. PTP-oc is structurally unique in that, unlike most known transmembrane PTPs, it has a short extracellular region (eight residues), lacks a signal peptide proximal to the N-terminus, and contains only a single ‘PTP catalytic domain’. The PTP catalytic domain shows 45–50% sequence identity with the catalytic domain of human HPTPβ and with the first catalytic domain of LCA. The PTP-oc gene exists as a single copy in the rabbit genome. The corresponding mRNA (3.8 kb) is expressed in osteoclasts but not in other bone-derived cells (e.g. osteoblasts and stromal cells). The 3.8 kb PTP-oc mRNA transcript was also expressed in the rabbit brain, kidney and spleen. However, the brain and kidney, but not osteoclasts or spleen, also expressed a larger transcript (6.5 kb). The PTP catalytic domain of PTP-oc was expressed as a GST–cPTP-oc fusion protein. In vitro phosphatase assays indicated that the purified fusion protein exhibited phosphatase activities at neutral pH values toward p-nitrophenyl phosphate, phosphotyrosyl Raytide, and phosphotyrosyl histone, whereas it had no appreciable activity toward phosphoseryl casein. In summary, we have: (a) cloned and sequenced the putative full-length cDNA of a unique PTP (PTP-oc) from rabbit osteoclasts; (b) shown that the mature 3.8 kb PTP-oc mRNA was expressed primarily in osteoclasts and the spleen; and (c) shown that the PTP-oc fusion protein exhibited a phosphotyrosine-specific phosphatase activity. In conclusion, PTP-oc represents a structurally unique subfamily of transmembrane PTPs.

Molecular cloning and characterization of gut-derived cysteine proteinases associated with a host protective extract from Haemonchus contortus

Parasitology ◽  
1999 ◽  
Vol 119 (4) ◽  
pp. 405-412 ◽  
Author(s):  
P. J. SKUCE ◽  
D. L. REDMOND ◽  
S. LIDDELL ◽  
E. M. STEWART ◽  
G. F. J. NEWLANDS ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Southern Blot Analysis ◽  
Single Copy ◽  
Blood Feeding ◽  
Cdna Expression Library ◽  
Cysteine Proteinases ◽  
Rt Pcr ◽  
Expression Library ◽  
Developmentally Regulated

Cysteine proteinases have been implicated in the protection conferred by vaccination with detergent-soluble extracts of Haemonchus contortus. In the present study, antisera from sheep refractory to Haemonchus challenge following vaccination with a ‘proteinase-enriched’ Haemonchus gut membrane extract, were employed to screen a cDNA expression library of the adult parasite. This resulted in the isolation of 3 cDNAs (designated hmcp1, 4 and 6) encoding cathepsin B-like cysteine proteinases. Immunocytochemical studies specifically localized the products of these genes to the microvillar surface of the parasite's gut and RT–PCR experiments revealed that these were developmentally regulated, being expressed exclusively during the blood-feeding parasitic stages. In addition, a generic PCR approach was adopted in order to identify the predominant cysteine proteinases in a UK strain of Haemonchus. A panel of 5 cDNAs, including hmcp1 and 4, was amplified in this way. Genomic Southern blot analysis indicated that some of these enzymes were encoded by single-copy genes, whereas others were encoded by multi-copy genes. Subsequent sequence analysis revealed that the proteases identified in this study were distinct from those previously reported in USA strains of the parasite.

scholarly journals Developmentally regulated protein-tyrosine kinase genes in Dictyostelium discoideum.

1990 ◽  
Vol 10 (7) ◽  
pp. 3578-3583 ◽  
Author(s):  
J L Tan ◽  
J A Spudich
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Dictyostelium Discoideum ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Model Organism ◽  
Cdna Expression Library ◽  
Expression Library ◽  
Developmentally Regulated ◽  
Protein Tyrosine

Dictyostelium discoideum, an organism that undergoes development and that is amenable to biochemical and molecular genetic approaches, is an attractive model organism with which to study the role of tyrosine phosphorylation in cell-cell communication. We report the presence of protein-tyrosine kinase genes in D. discoideum. Screening of a Dictyostelium cDNA expression library with an anti-phosphotyrosine antibody identifies fusion proteins that exhibit protein-tyrosine kinase activity. Two distinct cDNAs were identified and isolated. Though highly homologous to protein kinases in general, these kinases do not exhibit many of the hallmarks of protein-tyrosine kinases of higher eucaryotes. In addition, these genes are developmentally regulated, which suggests a role for tyrosine phosphorylation in controlling Dictyostelium development.

scholarly journals Brain-specific expression of MAP2 detected using a cloned cDNA probe.

1986 ◽  
Vol 102 (6) ◽  
pp. 2098-2105 ◽  
Author(s):  
S A Lewis ◽  
A Villasante ◽  
P Sherline ◽  
N J Cowan
Keyword(s):  
Fusion Protein ◽  
Mouse Brain ◽  
Single Gene ◽  
Cdna Probe ◽  
Expression Vectors ◽  
Cdna Expression Library ◽  
Expression Library ◽  
Mrna Molecule ◽  
Mouse Tissues ◽  
Cloned Cdna

We describe the isolation of a set of overlapping cDNAs encoding mouse microtubule associated protein 2 (MAP2), using an anti-MAP antiserum to screen a mouse brain cDNA expression library cloned in bacteriophage lambda gt11. The authenticity of these clones was established by the following criteria: (a) three non-identical clones each expressing a MAP2 immunoreactive fusion protein were independently isolated from the expression library; each of these clones cross-hybridized at the nucleic acid level; (b) anti-MAP antiserum was affinity purified using nitrocellulose-bound fusion protein; these antibodies detected only MAP2 in an immunoblot experiment of whole brain microtubule protein; (c) a series of cDNA "walking" experiments was done so as to obtain a non-overlapping cloned fragment corresponding to a different part of the same mRNA molecule. Upon subcloning this non-overlapping fragment into plasmid expression vectors, a fusion protein was synthesized that was immunoreactive with an anti-MAP2 specific antiserum. Thus, a single contiguous cloned mRNA molecule encodes at least two MAP2-specific epitopes; (d) the cloned cDNA probes detect an mRNA species in mouse brain that is of a size (approximately 9 kb) consistent with the coding capacity required by a 250,000-D protein. The MAP2-specific cloned cDNA probes were used in RNA blot transfer experiments to assay for the presence of MAP2 mRNA in a variety of mouse tissues. Though brain contained abundant quantities of MAP2 mRNA, no corresponding sequences were detectable in RNA prepared from liver, kidney, spleen, stomach, or thymus. We conclude that the expression of MAP2 is brain-specific. Use of the MAP2 specific cDNA probes in genomic Southern blot transfer experiments showed the presence of a single gene encoding MAP2 in mouse. The microheterogeneity of MAP2 is therefore ascribable either to alternative splicing within a single gene, or to posttranslational modification(s), or both. Under conditions of low stringency, the mouse MAP2 cDNA probe cross-hybridizes with genomic sequences from rat, human, and (weakly) chicken, but not with sequences in frog, Drosophila, or sea urchin DNA. Thus, there is significant interspecies divergence of MAP2 sequences. The implications of the above observations are discussed in relationship to the potential biological function of MAP2.

A novel 205-kilodalton testis-specific serine/threonine protein kinase associated with microtubules of the spermatid manchette

1993 ◽  
Vol 13 (12) ◽  
pp. 7625-7635
Author(s):  
P D Walden ◽  
N J Cowan
Keyword(s):  
Protein Complex ◽  
Catalytic Domain ◽  
Signal Transduction Pathway ◽  
Kinase Domain ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Expression Library ◽  
Serine Threonine Kinase ◽  
Expression Clone

To identify proteins which interact with and potentially modulate the function of microtubules during spermatogenesis, we prepared a total testis MAP (microtubule-associated protein) antiserum and used it to isolate cDNA clones from a mouse testis cDNA expression library. Antibodies affinity purified by using one expression clone recognized a 205-kDa protein, termed MAST205, which colocalizes with the spermatid manchette. Sequencing of full-length cDNA clones encoding MAST205 revealed it to be a novel serine/threonine kinase with a catalytic domain related to those of the A and C families. The testis-specific MAST205 RNA increases in abundance during prepuberal testis development, peaking at the spermatid stage. The microtubule-binding region of MAST205 occupies a central region of the molecule including the kinase domain and sequences C terminal to this domain. Binding of MAST205 to microtubules requires interaction with other MAPs, since it does not bind to MAP-free tubulin. A 75-kDa protein associated with immunoprecipitates of MAST205 from extracts of both whole testis and testis microtubules becomes phosphorylated in in vitro kinase assays. This 75-kDa substrate of the MAST205 kinase may form part of the MAST205 protein complex which binds microtubules. The MAST205 protein complex may function to link the signal transduction pathway with the organization of manchette microtubules.

Developmentally regulated protein-tyrosine kinase genes in Dictyostelium discoideum

1990 ◽  
Vol 10 (7) ◽  
pp. 3578-3583
Author(s):  
J L Tan ◽  
J A Spudich
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Dictyostelium Discoideum ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Model Organism ◽  
Cdna Expression Library ◽  
Expression Library ◽  
Developmentally Regulated ◽  
Protein Tyrosine

Dictyostelium discoideum, an organism that undergoes development and that is amenable to biochemical and molecular genetic approaches, is an attractive model organism with which to study the role of tyrosine phosphorylation in cell-cell communication. We report the presence of protein-tyrosine kinase genes in D. discoideum. Screening of a Dictyostelium cDNA expression library with an anti-phosphotyrosine antibody identifies fusion proteins that exhibit protein-tyrosine kinase activity. Two distinct cDNAs were identified and isolated. Though highly homologous to protein kinases in general, these kinases do not exhibit many of the hallmarks of protein-tyrosine kinases of higher eucaryotes. In addition, these genes are developmentally regulated, which suggests a role for tyrosine phosphorylation in controlling Dictyostelium development.

scholarly journals Cloning and Expression of a 48-KilodaltonBabesia caballi Merozoite Rhoptry Protein and Potential Use of the Recombinant Antigen in an Enzyme-Linked Immunosorbent Assay

1999 ◽  
Vol 37 (11) ◽  
pp. 3475-3480 ◽  
Author(s):  
Hiromi Ikadai ◽  
Xuenan Xuan ◽  
Ikuo Igarashi ◽  
Shigeyasu Tanaka ◽  
Takumi Kanemaru ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Cloning And Expression ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cdna Expression Library ◽  
Expression Library ◽  
Infected Horse ◽  
Babesia Caballi ◽  
Reading Frame ◽  
Highly Sensitive ◽  
Rhoptry Protein

A cDNA expression library prepared from Babesia caballimerozoite mRNA was screened with a monoclonal antibody BC11D against the rhoptry protein of B. caballi merozoite. A cDNA encoding a 48-kDa protein of B. caballi was cloned and designated BC48. The complete nucleotide sequence of the BC48 gene had 1,828 bp and was shown to contain no intron. Southern blotting analysis indicated that the BC48 gene contained more than two copies in theB. caballi genome. Computer analysis suggested that this sequence contained an open reading frame of 1,374 bp with a coding capacity of approximately 52 kDa. The recombinant protein expressed by the vaccinia virus vector in horse cells had an apparent molecular mass of 48 kDa, which was the same as that of the native B. caballi 48-kDa protein. Moreover, recombinant proteins expressed by the pGEX4T expression vector in Escherichia coli as glutathione S-transferase fusion proteins were used for antigen in an enzyme-linked immunosorbent assay (ELISA). The ELISA was able to differentiate very clearly between B. caballi-infected horse sera and B. equi-infected horse sera or noninfected normal horse sera. These results suggest that this simple and highly sensitive test might be applicable to the detection of B. caballi-infected horses in the field.

Cloning and expression of a cDNA that comprises part of the gene coding for a spore coat protein of Dictyostelium discoideum

1984 ◽  
Vol 4 (11) ◽  
pp. 2273-2278
Author(s):  
B C Dowds ◽  
W F Loomis
Keyword(s):  
Dictyostelium Discoideum ◽  
Cdna Clone ◽  
Single Gene ◽  
Polyclonal Antiserum ◽  
Cloning And Expression ◽  
Spore Coat ◽  
Coat Proteins ◽  
Developmentally Regulated ◽  
Gene Coding ◽  
Spore Coat Proteins

The three major spore coat proteins of Dictyostelium discoideum are developmentally regulated, cell-type-specific proteins. They are packaged in prespore vesicles and then secreted to form the outer layer of spore coats. We have isolated a cDNA clone from the gene coding for one of these proteins, SP96, a glycoprotein of 96,000 daltons. We screened the cDNA bank by the method of hybrid select translation followed by immunoprecipitation of the translation products with SP96-specific polyclonal antiserum. We found that the gene was first transcribed into stable mRNA a few hours before the time of detection of SP96 synthesis and that the mRNA, like the protein, accumulated specifically in prespore cells and spores. SP96 constituted the same proportion of newly synthesized protein as the proportion of its message in polyadenylated RNA. SP96 appeared to be encoded by a single gene as judged by Southern blot analysis of digested genomic DNA hybridized to the cDNA clone.

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