The object of the present invention is to provide a novel protein having a
kinase activity and a gene encoding said protein. According to the
present invention, there is provided a GANP protein which is represented
by the amino acid sequence shown in SEQ ID No. 1 or No. 3 of the sequence
listing, and is involved in the signal conversion of abnormal B cell
differentiation in an autoimmune state, and has a kinase activity, and a
polynucleotide which encodes said protein.