Development, Vol 122, Issue 10 3295-3305, Copyright © 1996 by Company of Biologists

JOURNAL ARTICLES

The Dictyostelium dual-specificity kinase splA is essential for spore differentiation

GH Nuckolls, N Osherov, WF Loomis and JA Spudich
Department of Biochemistry, Stanford University School of Medicine, CA 94305, USA. gn18s@nih.gov

We have studied the structure and function of the Dictyostelium kinase splA. A truncated form of the splA protein exhibited primarily tyrosine kinase activity in vitro; however, it also autophosphorylated on serine and threonine residues. The kinase domain of splA exhibits approximately 38% identity to the CTR1 kinase of Arabidopsis, which is a member of the Raf family. Outside its kinase domain, splA shares homology with the byr2 kinase of S. pombe. By aligning the sequences of splA, byr2 and STE11, a homologue of byr2 in S. cerevisiae, we have identified a conserved motif that is also found in members of the Eph family of growth factor receptor tyrosine kinases. SplA is expressed throughout development with a peak during the mound stage of morphogenesis. Strains in which the splA gene had been disrupted completed fruiting body formation; however, spore cells spontaneously lysed before completing their differentiation. Northern analysis revealed the expression of the prespore marker cotB and the prestalk markers ecmA and ecmB in the mutant strain during development. The spore differentiation marker spiA was detected in the mutant spores both by northern and immunoblotting, but these cells failed to assemble spore coats. Immunoblot analysis of the developmental pattern of tyrosine phosphorylation revealed a protein that was phosphorylated in mutants but was not phosphorylated in the wild-type cells. SplA is a novel dual specificity kinase that regulates the differentiation of spore cells.

This article has been cited by other articles:

				R. Yoshino, T. Morio, Y. Yamada, H. Kuwayama, M. Sameshima, Y. Tanaka, H. Sesaki, and M. Iijima Regulation of Ammonia Homeostasis by the Ammonium Transporter AmtA in Dictyostelium discoideum Eukaryot. Cell, December 1, 2007; 6(12): 2419 - 2428. [Abstract] [Full Text] [PDF]

				P. Torija, J. J. Vicente, T. B. Rodrigues, A. Robles, S. Cerdan, L. Sastre, R. M. Calvo, and R. Escalante Functional genomics in Dictyostelium: MidA, a new conserved protein, is required for mitochondrial function and development J. Cell Sci., March 15, 2006; 119(6): 1154 - 1164. [Abstract] [Full Text] [PDF]

				D. L. Beck, D. R. Boettner, B. Dragulev, K. Ready, T. Nozaki, and W. A. Petri Jr. Identification and Gene Expression Analysis of a Large Family of Transmembrane Kinases Related to the Gal/GalNAc Lectin in Entamoeba histolytica Eukaryot. Cell, April 1, 2005; 4(4): 722 - 732. [Abstract] [Full Text] [PDF]

				C. M. West, P. Zhang, A. C. McGlynn, and L. Kaplan Outside-In Signaling of Cellulose Synthesis by a Spore Coat Protein in Dictyostelium Eukaryot. Cell, April 1, 2002; 1(2): 281 - 292. [Abstract] [Full Text] [PDF]

				S.-H. Shiu and A. B. Bleecker Receptor-like kinases from Arabidopsis form a monophyletic gene family related to animal receptor kinases PNAS, August 23, 2001; (2001) 181141598. [Abstract] [Full Text] [PDF]

				J. Moniakis, S. Funamoto, M. Fukuzawa, J. Meisenhelder, T. Araki, T. Abe, R. Meili, T. Hunter, J. Williams, and R. A. Firtel An SH2-domain-containing kinase negatively regulates the phosphatidylinositol-3 kinase pathway Genes & Dev., March 15, 2001; 15(6): 687 - 698. [Abstract] [Full Text]

				Y Kishi, C Clements, D. Mahadeo, D. Cotter, and M Sameshima High levels of actin tyrosine phosphorylation: correlation with the dormant state of Dictyostelium spores J. Cell Sci., January 10, 1998; 111(19): 2923 - 2932. [Abstract] [PDF]

				R Escalante and L Sastre A Serum Response Factor homolog is required for spore differentiation in Dictyostelium Development, January 10, 1998; 125(19): 3801 - 3808. [Abstract] [PDF]

				S.-H. Shiu and A. B. Bleecker Receptor-like kinases from Arabidopsis form a monophyletic gene family related to animal receptor kinases PNAS, September 11, 2001; 98(19): 10763 - 10768. [Abstract] [Full Text] [PDF]