Table 1.

Phosphorylation sites of murine βPIXa detected by mass spectrometry

Site	Detected in serum-incubated sample	Detected in EGF-stimulated sample	Homologs/other family members	Putative kinases
S71	+	+	R, M, H/αPIX	CDC2, CDK5
S79	Not covered	+	R, M, H	CDC2, CDK5
S131	+	+	R, M, H
S135	+		R, M, H
S145	+		R, M
S146	+		R, M, H
S192	+	+	R, M, H/αPIX
S195	+	+	R, M
S340		+	R, M, H/αPIX
S427/S428		+	R, M, H/αPIX (S428 only)
S498	IMAC	Not covered	R, M, H/αPIX	CDC2, CDK5
S516	+	+	R, M, H/αPIX	PKA
Y542	IMAC		R, M, H/αPIX
S559	IMAC	IMAC	R, M, H/αPIX	PKA, AKT, 14-3-3
S588	Not covered	+	R, M, H/αPIX	PKCmu
T592		+	R, M, H/αPIX

Serum-incubated and EGF-stimulated samples were both treated with calyculin A and peroxovanadate to inhibit phosphatases. Phosphorylation sites labeled ‘IMAC’ were only detected after sample enrichment by immobilized metal affinity chromatography (IMAC). Sites detected without enrichment are denoted with a ‘+’. ‘Not covered’ signifies that the residue was not observed during mass spectrometry analysis, therefore phosphorylation status could not be determined. Homologous phosphorylation sites were determined via sequence comparison analysis using FASTA (http://fasta.bioch.virginia.edu/) (Pearson, 1990). Consensus phosphorylation motifs for putative kinases were analyzed using the Scansite scoring algorithm (http://scansite.mit.edu) (Obenauer et al., 2003). For additional data regarding βPIXa phosphorylation, see the Cell Migration Consortium website: http://www.cellmigration.org. R, rat; M, mouse; H, human.