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.
1. An antibody which recognizes the protein having the amino acid sequence shown in SEQ ID No. 1.
2. An antibody of a variant protein having a kinase activity substantially similar to an isolated protein having the amino acid sequence shown in SEQ ID No. 1, wherein 1-20 amino acids are deleted, substituted, and/or added.