H-Invitational Database (H-InvDB; http://www.h-invitational.jp/) is an integrated database of human genes, transcripts and proteins (Fig. 1.). By extensive analyses of all human transcripts, we provide curated annotations of human genes and transcripts that include gene structures, alternative splicing isoforms, non-coding functional RNAs, protein functions, functional domains, sub-cellular localizations, metabolic pathways, protein 3D structure, genetic polymorphisms, relation with diseases, gene expression profiling, molecular evolutionary features, protein-protein interactions (PPIs) and gene families/groups.
H-InvDB provides human short protein dataset which amino acid length shorter than 80 a.a.. The total number of them, including those predicted from transcripts, is 7,096. We classified those human short proteins into six categories based on the similarities to known proteins and functional motifs, and currently we assigned function to 765 human short proteins (Table 1.). The coverage of those evidenced human short proteins is 2.2% (765/34,442) in the whole human proteome in H-InvDB release 5.0. The characterization of those human proteome dataset may lead to discoveries of novel human gene families.