Kinase Subfamily FAM198
Kinase Classification: Group Atypical: Family FJ: Subfamily FAM198
FAM198 is a subfamily of the Four-Jointed family of secretory kinases. It consists of two genes (FAM198A/C3orf41 and FAM198B/C4orf18) in vertebrates, and one or more homologs in other deuterostomes. The proteins are likely to be catalytically inactive, and are virtually unstudied
Protein Structure
Like other FJ family kinases, many FAM198 members have a conserved signal peptide, and many have a TM region just downstream. A weakly-conserved 100-200 AA N-terminal region is then followed by the C-terminal kinase domain. The kinase domain lacks homology to the other FJ subfamilies within the catalytic loop, though it probably conserves the K72-E91 salt bridge and the D184 Mg-co-ordinating residue.
Protein Interactions
No protein interactions have been reported for any member of this family (Feb 2012), and no phosphorylation has been seen.
Evolution
Two members, FAM198A and FAM198B are found in all vertebrates, and several other members are seen in other deuterostomes, including Branchiostoma, Saccoglossus, and the sea urchin, S. purpuratus.
Functions
No FAM198 has been functionally characterized. The expression of FAM198B in mouse and Xenopus was reported, and shown to be downstream of FGF and maybe basement membrane signaling [1]. A GFP-fusion of FAM198B was reportedly localized in the Golgi, similar to the localization of FJX1 [2]. Data from the Protein Atlas show localization of human FAM198B to the nucleus
