HUGE: a database for human large proteins identified by Kazusa cDNA sequencing project.

HUGE is a database for human large proteins newly identified by Kazusa cDNA project, which aims to predict protein primary structures from sequences of human large cDNAs (>4 kb). In particular, cDNA clones capable of coding for large proteins (>50 kDa) are current targets of the project. More than 700 sequences of human cDNAs (average size, 5.1 kb) have been determined to date and deposited in the public databases. Notable information implied from the cDNAs and the predicted protein sequences can be obtained through HUGE via the World Wide Web at URL http://www.kazusa.or.jp/huge     

HUGE: a database for human large proteins identified in the Kazusa cDNA sequencing project

We have been developing a HUGE database to summarize results from the sequence analysis of human novel large (>4 kb) cDNAs identified in the Kazusa cDNA sequencing project, systematically designated KIAA plus a four-digit number. HUGE currently contains nearly 2000 gene/protein characteristic tables harboring the results of the computer-assisted analysis of the cDNA and the predicted protein sequences together with those of expression profiling and chromosomal mapping. In the updated version of HUGE, we made it possible to compare each KIAA cDNA sequence with the corresponding entry in the human draft genome sequence that was published recently. Approximately 90% of KIAA cDNAs in HUGE can be localized along the human genome for at least half or more of the cDNA’s length. Any nucleotide differences between the cDNA and the corresponding genomic sequences are also presented in detail. This new version of HUGE greatly helps us evaluate the completeness of cDNA clones and the accuracy of cDNA/genomic sequences. More interestingly, in some cases, the ability to compare cDNA with genomic sequences allows us to identify candidate sites of RNA editing. HUGE is available on the World Wide Web at http://www.kazusa.or.jp/huge.     

Prediction of the coding sequences of mouse homologues of KIAA gene: III. the complete nucleotide sequences of 500 mouse KIAA-homologous cDNAs identified by screening of terminal sequences of cDNA clones randomly sampled from size-fractionated libraries.

We have conducted a human cDNA project to predict protein-coding sequences (CDSs) in large cDNAs (> 4 kb) since 1994, and the number of newly identified genes, known as KIAA genes, already exceeds 2000. The ultimate goal of this project is to clarify the physiological functions of the proteins encoded by KIAA genes. To this end, the project has recently been expanded to include isolation and characterization of mouse KIAA-counterpart genes. We herein present the entire sequences and the chromosome loci of 500 mKIAA cDNA clones and 13 novel cDNA clones that were incidentally identified during this project. The average size of the 513 cDNA sequences reached 4.3 kb and that of the deduced amino acid sequences from these cDNAs was 816 amino acid residues. By comparison of the predicted CDSs between mouse and human KIAAs, 12 mKIAA cDNA clones were assumed to be differently spliced isoforms of the human cDNA clones. The comparison of mouse and human sequences also revealed that four pairs of human KIAA cDNAs are derived from single genes. Notably, a homology search against the public database indicated that 4 out of 13 novel cDNA clones were homologous to the disease-related genes.     

Prediction of the coding sequences of mouse homologues of KIAA gene: I. The complete nucleotide sequences of 100 mouse KIAA-homologous cDNAs identified by screening of terminal sequences of cDNA clones randomly sampled from size-fractionated libraries.

We have been conducting a human cDNA project to predict protein-coding sequences in long cDNAs (> 4 kb) since 1994. The number of these newly identified human genes exceeds 2000 and these genes are known as KIAA genes. As an extension of this project, we herein report characterization of cDNAs derived from mouse KIAA-homologous genes. A primary aim of this study was to prepare a set of mouse. KIAA-homologous cDNAs that could be used to analyze the physiological roles of KIAA genes in mice. In addition, comparison of the structures of mouse and human KIAA cDNAs might enable us to evaluate the integrity of KIAA cDNAs more convincingly. In this study, we selected mouse KIAA-homologous cDNA clones to be sequenced by screening a library of terminal sequences of mouse cDNAs in size-fractionated libraries. We present the entire sequences of 100 cDNA clones thus selected and predict their protein-coding sequences. The average size of the 100 cDNA sequences reached 5.1 kb and that of mouse KIAA-homologous proteins predicted from these cDNAs was 989 amino acid residues.     

Characterization of long cDNA clones from human adult spleen. II. The complete sequences of 81 cDNA clones.

To accumulate information on the coding sequences (CDSs) of unidentified genes, we have conducted a sequencing project of human long cDNA clones. Both the end sequences of approximately 10,000 cDNA clones from two size-fractionated human spleen cDNA libraries (average sizes of 4.5 kb and 5.6 kb) were determined by single-pass sequencing to select cDNAs with unidentified sequences. We herein present the entire sequences of 81 cDNA clones, most of which were selected by two approaches based on their protein-coding potentialities in silico: Fifty-eight cDNA clones were selected as those having protein-coding potentialities at the 5'-end of single-pass sequences by applying the GeneMark analysis; and 20 cDNA clones were selected as those expected to encode proteins larger than 100 amino acid residues by analysis of the human genome sequences flanked by both the end sequences of cDNAs using the GENSCAN gene prediction program. In addition to these newly identified cDNAs, three cDNA clones were isolated by colony hybridization experiments using probes corresponding to known gene sequences since these cDNAs are likely to contain considerable amounts of new information regarding the genes already annotated. The sequence data indicated that the average sizes of the inserts and corresponding CDSs of cDNA clones analyzed here were 5.0 kb and 2.0 kb (670 amino acid residues), respectively. From the results of homology and motif searches against the public databases, functional categories of the 29 predicted gene products could be assigned; 86% of these predicted gene products (25 gene products) were classified into proteins relating to cell signaling/communication, nucleic acid management, and cell structure/motility.     

Prediction of the coding sequences of mouse homologues of KIAA gene: IV. The complete nucleotide sequences of 500 mouse KIAA-homologous cDNAs identified by screening of terminal sequences of cDNA clones randomly sampled from size-fractionated libraries.

We have been conducting a mouse cDNA project to predict protein-coding sequences of mouse homologues of human KIAA and FLJ genes since 2001. As an extension of these projects, we herein present the entire sequences of 500 mKIAA cDNA clones and 4 novel cDNA clones that were incidentally identified during this project. We have isolated cDNA clones from the size-fractionated mouse cDNA libraries derived from 7 tissues and 3 types of cultured cells. The average size of the 504 cDNA sequences reached 4.3 kb and that of the deduced amino acid sequences from these cDNAs was 807 amino acid residues. We assigned the integrity of CDSs from the comparison with the corresponding human KIAA cDNA sequences. The comparison of mouse and human sequences revealed that two different human KIAA cDNAs are derived from single genes. Furthermore, 3 out of 4 proteins encoded in the novel cDNA clones showed moderate sequence similarity with human KIAA proteins, thus we could obtain new members of KIAA protein families through our mouse cDNA projects.     

Construction of expression-ready cDNA clones for KIAA genes: manual curation of 330 KIAA cDNA clones.

We have accumulated information on protein-coding sequences of uncharacterized human genes, which are known as KIAA genes, through cDNA sequencing. For comprehensive functional analysis of the KIAA genes, it is necessary to prepare a set of cDNA clones which direct the synthesis of functional KIAA gene products. However, since the KIAA cDNAs were derived from long mRNAs (> 4 kb), it was not expected that all of them were full-length. Thus, as the first step toward preparing these clones, we evaluated the integrity of protein-coding sequences of KIAA cDNA clones through comparison with homologous protein entries in the public database. As a result, 1141 KIAA cDNAs had at least one homologous entry in the database, and 619 of them (54%) were found to be truncated at the 5' and/or 3' ends. In this study, 290 KIAA cDNA clones were tailored to be full-length or have considerably longer sequences than the original clones by isolating additional cDNA clones and/or connected parts of additional cDNAs or PCR products of the missing portion to the original cDNA clone. Consequently, 265, 8, and 17 predicted CDSs of KIAA cDNA clones were increased in the amino-, carboxy-, and both terminal sequences, respectively. In addition, 40 cDNA clones were modified to remove spurious interruption of protein-coding sequences. The total length of the resultant extensions at amino- and carboxy-terminals of KIAA gene products reached 97,000 and 7,216 amino acid residues, respectively, and various protein domains were found in these extended portions.     

Kazusa mammalian cDNA resources: towards functional characterization of KIAA gene products.

The Kazusa cDNA project pioneered an extensive sequencing project of human cDNAs in their entirety and focused sequencing efforts particularly on large cDNAs encoding large proteins. More than 2000 human genes, referred to as 'KIAA' genes, were initially identified through this cDNA project. Since many KIAA genes still remain functionally uncharacterized, our current focus is to determine their biological functions in vivo. In this review, we describe the current status of the Kazusa mammalian cDNA resources and the future direction of the functional characterization of KIAA genes.     

The Kazusa cDNA project for identification of unknown human transcripts

The Kazusa cDNA project is unique by its focus on sequencing large human cDNAs (>4 kb). We describe an overview of the human cDNA sequence data accumulated during the first phase of the project on over 2000 cDNAs and its integration with the genome sequence. In the second phase of the project, which aims at bridging the human genome and proteome using the output of the first phase, we are very carefully evaluating our cDNA clones and, when necessary, experimentally revising them.     

Prediction of the coding sequences of mouse homologues of KIAA gene: II. The complete nucleotide sequences of 400 mouse KIAA-homologous cDNAs identified by screening of terminal sequences of cDNA clones randomly sampled from size-fractionated libraries.

We have accumulated information of the coding sequences of uncharacterized human genes, which are known as KIAA genes, and the number of these genes exceeds 2000 at present. As an extension of this sequencing project, we recently have begun to accumulate mouse KIAA-homologous cDNAs, because it would be useful to prepare a set of human and mouse homologous cDNA pairs for further functional analysis of the KIAA genes. We herein present the entire sequences of 400 mouse KIAA cDNA clones and 4 novel cDNA clones which were incidentally identified during this project. Most of clones entirely sequenced in this study were selected by computer-assisted analysis of terminal sequences of the cDNAs. The average size of the 404 cDNA sequences reached 5.3 kb and that of the deduced amino acid sequences from these cDNAs was 868 amino acid residues. The results of sequence analyses of these clones showed that single mouse KIAA cDNAs bridged two different human KIAA cDNAs in some cases, which indicated that these two human KIAA cDNAs were derived from single genes although they had been supposed to originate from different genes. Furthermore, we successfully mapped all the mouse KIAA cDNAs along the genome using a recently published mouse genome draft sequence.     

A comprehensive approach for establishment of the platform to analyze functions of KIAA proteins II: public release of inaugural version of InGaP database containing gene/protein expression profiles for 127 mouse KIAA genes/proteins.

The inaugural version of the InGaP database (Integrative Gene and Protein expression database; http://www.kazusa.or.jp/ingap/index.html) is a comprehensive database of gene/protein expression profiles of 127 mKIAA genes/proteins related to hypothetical ones obtained in our ongoing cDNA project. Information about each gene/protein consists of cDNA microarray analysis, subcellular localization of the ectopically expressed gene, and experimental data using anti-mKIAA antibody such as Western blotting and immunohistochemical analyses. KIAA cDNAs and their mouse counterparts, mKIAA cDNAs, were mainly isolated from cDNA libraries derived from brain tissues, thus we expect our database to contribute to the field of neuroscience. In fact, cDNA microarray analysis revealed that nearly half of our gene collection is predominantly expressed in brain tissues. Immunohistochemical analysis of the mouse brain provides functional insight into the specific area and/or cell type of the brain. This database will be a resource for the neuroscience community by seamlessly integrating the genomic and proteomic information about the mouse KIAA genes/proteins.     

Sequencing and Analysis of Approximately 40 000 Soybean cDNA Clones from a Full-Length-Enriched cDNA Library

A large collection of full-length cDNAs is essential for the correct annotation of genomic sequences and for the functional analysis of genes and their products. We obtained a total of 39 936 soybean cDNA clones (GMFL01 and GMFL02 clone sets) in a full-length-enriched cDNA library which was constructed from soybean plants that were grown under various developmental and environmental conditions. Sequencing from 5′ and 3′ ends of the clones generated 68 661 expressed sequence tags (ESTs). The EST sequences were clustered into 22 674 scaffolds involving 2580 full-length sequences. In addition, we sequenced 4712 full-length cDNAs. After removing overlaps, we obtained 6570 new full-length sequences of soybean cDNAs so far. Our data indicated that 87.7% of the soybean cDNA clones contain complete coding sequences in addition to 5′- and 3′-untranslated regions. All of the obtained data confirmed that our collection of soybean full-length cDNAs covers a wide variety of genes. Comparative analysis between the derived sequences from soybean and Arabidopsis, rice or other legumes data revealed that some specific genes were involved in our collection and a large part of them could be annotated to unknown functions. A large set of soybean full-length cDNA clones reported in this study will serve as a useful resource for gene discovery from soybean and will also aid a precise annotation of the soybean genome.Key words: EST, full-length cDNA, functional annotation, legume, soybean