title: Identification of an Efs isoform that lacks the SH3 domain and chromosomal mapping of human Efs.
abstract: Efs was originally found by expression cloning of a mouse embryo cDNA library through its Fyn-SH3 binding capacity (Ishino et al., Oncogene 11, 2331-2338, 1995). Efs has characteristic regions important in intracellular signal transduction; these are an SH3 domain, a cluster of putative ligands for SH2 domains and proline-rich sequences with SH3-binding consensus. In this paper, we report cDNA cloning of human Efs and a variant of it from a hippocampal cDNA library. The human Efs gene was mapped to chromosome 14q11.2-q12 by fluorescence in situ hybridization. We identified two forms of human Efs, designated hEfs1 and hEfs2. hEfs1 represents the human counterpart of original mouse embryo Efs (mEfs1). hEfs2, the newly identified form, is identical to hEfs1, except for its lack of the SH3 domain. hEfs1 and mEfs1 are 80% identical in their amino acid sequences and 100% identical within the SH3 domain. Reverse transcription polymerase chain reaction analysis of adult mouse tissue RNA indicated expression of Efs2 and of Efs1 in various tissues. Evidence suggesting the presence of the Efs2 protein in human tissue was obtained by immunoprecipitation followed by immunoblotting with two different anti-Efs antibodies. Possible functions of Efs2 are discussed.
authors.affiliation: Department of Biochemistry, Cancer Research Institute, Sapporo Medical University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ishino
authors.forename: T
authors.initials: T
authors.lastname: Ohba
authors.forename: J
authors.initials: J
authors.lastname: Inazawa
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Ariyama
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002883:Chromosomes, Human, Pair 14; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017384:Sequence Deletion; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C484351:EFS protein, human; C097281:Efs protein, mouse; D010750:Phosphoproteins; D012333:RNA, Messenger