Organization of the Chick CDC37 Gene

Abstract

CDC37 and the chaperone protein, Hsp90, form a complex that binds to several kinases, resulting in stabilization and promotion of their activity. CDC37 also binds DNA and glycosaminoglycans in a sequence-specific manner. In this study, we further characterize chick CDC37 and examine the organization of the CDC37 gene. Chick CDC37 is a ϳ50-kDa protein encoded by an mRNA of ϳ1.7 kilobases. The CDC37 gene is ϳ8.5 kilobases and contains 8 exons and 7 introns of various sizes. The presumptive promoter and 5 -flanking regions contain an E2 box and consensus binding sites for SP1, for the S8 homeodomain protein, and for two zinc finger clusters within the myeloid progenitor transcription factor, MZF1. Particularly striking is a ϳ470-base pair region composed of a highly repetitive 10 -11-base pair sequence, (T/C)gCTAT(A/G)GGG(A/T) (where g represents the additional G present in the 11-base pair sequence). This region includes 15 copies of the sequence, TAT-GGGGA, which conforms to the DNA consensus sequence recognized by one of the zinc finger clusters in MZF1. These findings emphasize the potential importance of CDC37 in regulation of cellular behavior during tissue development and reorganization.

Molecular Characterization of a Novel Intracellular Hyaluronan-binding Protein

“…Characterization of Chick IHABP4 Gene-To analyze the organization of the IHABP4 gene, we used a long PCR strategy by which we determined CDC37 gene organization (15). Because the chick genomic region covering the LH21 cDNA could not be directly amplified by a single long PCR, numerous primers in both forward and reverse directions were designed along the cDNA sequence.…”

“…Using the monoclonal antibody (mAb), IVd4, which recognizes a novel group of chick HABPs (14), we have previously identified and characterized CDC37, a cell cycle regulatory protein (9,15). In the present study, we have characterized a cDNA, LH21, that encodes a second novel chick HABP recognized by mAb IVd4, using similar strategies as described previously (9,15).…”

“…In the present study, we have characterized a cDNA, LH21, that encodes a second novel chick HABP recognized by mAb IVd4, using similar strategies as described previously (9,15). This HABP, like CDC37, is also an intracellular protein containing multiple hyaluronan binding motifs, (R/ K)X 7 (R/K), in which B denotes arginine or lysine and X denotes any amino acid except glutamic or aspartic acid (16).…”

“…Cloning of PCR products and identification of boundary sequences between introns and exons were determined by the same strategy as previously used (15).…”

“…Total RNA and poly(A) ϩ RNA were prepared as described previously (15). Samples of the poly(A) ϩ RNA preparations were subjected to electrophoresis in a formaldehyde gel and then transferred to a nitrocellulose membrane.…”