Cloning, central nervous system expression and chromosomal mapping of the mouse PAK-1 and PAK-3 genes

Two cDNAs encoding PAK kinases were isolated from a mouse embryo library by screening with a PCR-generated probe derived from the kinase domain of a r at PAK kinase. These cDNAs, designated PAK-1 and PAK-3? encode mouse PAK ki nases of 545 and 544 amino acids, respectively. Both proteins possess an N- terminal Cdc42/Rac interacting binding domain (CRIB) and a C-terminal serin e/threonine kinase domain. Comparison of the two mouse PAK kinases revealed that the proteins show 87% amino acid identity. Northern analysis of a mul tiple mouse tissue blot with a PAK-1 probe detected a 3.0 kb transcript tha t was almost exclusively expressed in the brain and spinal cord compared to other tissues such as lung, liver and kidney. A similar pattern of central nervous system tissue expression of PAK-3 transcripts of 3.6 and 8 kb was also observed. Analysis of two multilocus genetic crosses localized Pak1 an d Pak3 to a position on chromosome 7 and X, respectively. The high level of PAK-1 and PAK-3 kinase expression in the mouse brain and spinal cord sugge sts a potentially important role for these kinases in the control of the ce llular architecture and/or signaling in the central nervous system. (C) 199 9 Published by Elsevier Science B.V. All rights reserved.