A cluster of keratin-associated proteins on mouse chromosome 10 in the region of conserved linkage with human chromosome 21

A gene cluster of three to five high-cysteine keratin-associated proteins ( KAPs) has been identified on mouse Chromosome 10 (MMU10) in the region of c onserved linkage with human chromosome 21 (HSA21), One of these genes, Krta p12-1, has been sequenced in its entirety and shown to be an intronless gen e encoding a predicted 130-amino-acid protein. Krtap12-1 is most closely re lated to two previously identified KAP4 genes, but variation in sequence an d cysteine content suggests that it represents a new RAP family, Krtap12-1 is expressed in the skin of a 3-day-old mouse, The corresponding region of HSA21, between ITGB2 (integrin beta 2) and PFKL (the liver isoform of phosp hofructokinase), has proven refractory to cloning, and thus mapping of this region at high resolution has been problematic. Based on the KAP gene clus ter position in mouse, evidence has been found for an orthologous human KAP cluster on HSA21q22.3, reinforcing the observation that comparative genomi cs can play an essential and practical role in determining mammalian genome organization. (C) 1998 Academic Press.