|
|
Article: Origin of Insulin Receptor-Like Tyrosine Kinases in Marine Sponges.
- Article from:
- The Biological Bulletin
- Article date:
- October 1, 1999
- Author:
CopyrightCOPYRIGHT 1999 Marine Biological Laboratory. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Introduction
The Porifera [sponges] are the oldest metazoan phylum; they existed 40 to 50 million years prior to the onset of the "Cambrian Explosion" (Valentine et al., 1996), the time of main divergence of metazoan phyla (Valentine, 1994). Highly conserved amino acid (aa) sequences in sponges indicate that the Porifera share one common ancestor with other metazoan phyla (Mtiller et al., 1994; also see Mtiller, 1995, 1997, and 1998). These sequences include those (i) for transmembrane receptors, e.g., transmembrane tyrosine kinase [TK] receptors [RTKs] (Muller and Schacke, 1996); (ii) for transmembrane adhesion molecules, e.g., the integrins (Pancer et al., ...