title: Ancient divergence of animal protein tyrosine kinase genes demonstrated by a gene family tree including choanoflagellate genes.
abstract: Animal-specific gene families involved in cell-cell communication and developmental control comprise many subfamilies with distinct domain structures and functions. They diverged by subfamily-generating duplications and domain shufflings before the parazoan-eumetazoan split. Here, we have cloned 40 PTK cDNAs from choanoflagellates, Monosiga ovata, Stephanoeca diplocostata and Codosiga gracilis, the closest relatives to animals. A phylogeny-based analysis of PTKs revealed that 40 out of 47 subfamilies analyzed have unique domain structures and are possibly generated independently in animal and choanoflagellate lineages by domain shufflings. Seven cytoplasmic subfamilies showed divergence before the animal-choanoflagellate split originated by both duplications and shufflings.
authors.affiliation: Department of Cell Biology, Biozentrum, University of Basel, Basel, Switzerland.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suga
authors.forename: Go
authors.initials: G
authors.lastname: Sasaki
authors.forename: Kei-Ichi
authors.initials: K
authors.lastname: Kuma
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nishiyori
authors.forename: Nozomi
authors.initials: N
authors.lastname: Hirose
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Su
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Iwabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyata
mesh_terms: D000818:Animals; D002816:Chordata, Nonvertebrate / Q000201:enzymology* / Q000235:genetics*; D018076:DNA, Complementary / Q000302:isolation & purification; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics*; D013045:Species Specificity
chemical_list: D018076:DNA, Complementary; D011505:Protein-Tyrosine Kinases