CDNA clone libraries

EST Profiling. An EST is a short, single sequence run collecting data over about 200-400 bases from a clone selected from a cCNA library. Typically, cDNA clone libraries... 

Expression vectors are engineered so that any cloned insert can be transcribed into RNA, and, in many instances, even translated into protein. cDNA expression libraries can be constructed in specially designed vectors derived from either plasmids or bacteriophage A. Proteins encoded by the various cDNA clones within such expression libraries can be synthesized in the host cells, and if suitable assays are available to identify a particular protein, its corresponding cDNA clone can be identified and isolated. Expression vectors designed for RNA expression or protein expression, or both, are available. 

The amino acid sequence of the human erythrocyte glucose transporter was deduced from the nucleotide sequence of a cDNA clone in 1985 [106]. Polyclonal antibodies raised against the protein were used to screen a Xgtl I cDNA library prepared from the human hepatocellular carcinoma cell line HepG2. (Like many other transformed... 

At this time, more then thirty channel DNAs have been cloned and characterized from various sources, predominantly from Drosophila melanogaster, mouse, rat and human cDNA/genomic libraries [6-31]. Inspection of the derived primary K channel protein sequences indicates that voltage-gated channels belong to a... 

Urinary proteins were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE), and a 70-kDa protein was identified as the major component of cat urine (Fig. 4.1 A). Comparative analysis of urinary proteins in several other mammals such as humans, mice, dogs, and cattle did not detect a 70-kDa protein. Therefore, the 70-kDa protein was purified from cat urine and characterized by biochemical methods (Miyazaki, Kamiie, Soeta, Taira and Yamashita 2003). Analysis of tissue distribution indicated that the 70-kDa protein is expressed in the kidney in a tissue-specific manner and secreted from the proximal straight tubular cells of the kidney into the urine (Fig. 4.IB). A full-length cDNA for a 70-kDa protein was cloned from a cat kidney cDNA library. The cDNA clone encoded a polypeptide of 545 amino acid residues. The deduced amino acid sequence shared 47% identity with cat carboxylesterase (CES, EC 3.1.1.1), and contained both the CES family protein motif (EDCLY) and a conserved active site motif (GESAG) associated with... 

Several groups have reported the isolation of cDNA clones for myeloperoxidase from cDNA libraries constructed from mRNA purified from HL-60 cells (Morishita et al. 1987 Weil et al. 1987). If such libraries are induced to express the proteins for which the cDNA molecules encode, then they can be screened for particular genes using antibodies. Indeed, this has been the approach used to isolate cDNA clones for myeloperoxidase from HL-60 cells. Full-length clones have been described and sequenced, and their identity confirmed by a variety of means ... 

Because the fMet-Leu-Phe receptor is present only at low levels in neutrophils (-12 x 10 15 g of receptor per cell), it has proved difficult to purify and characterise. Researchers have therefore turned to molecular cloning techniques to gain insight into the molecular structure of this receptor. This approach itself has not been easy because, in the absence of an antibody that specifically binds to the receptor, or else without some amino acid sequence data that can be used to synthesise oligonucleotide probes, cDNA libraries cannot be screened to isolate relevant clones. Therefore, experimental systems in which functional fMet-Leu-Phe receptors are expressed on the surfaces of transfected cells have been used. Two main systems have been utilised expression of mRNA injected into Xenopus laevis oocytes and cDNA cloning into the COS-cell expression vector. 

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