Purification of casein kinase I and isolation of cDNAs encoding multiple casein kinase I-like enzymes.
We have purified casein kinase I (CKI) over 6000-fold from bovine thymus and have sequenced seven tryptic peptides that account for nearly 25% of the primary sequence of the enzyme. By using PCR, partial cDNAs encoding CKI and a related enzyme (CKI-delta) were isolated. A product that may correspond to an alternatively spliced form of CKI was also detected. The CKI PCR product was used to probe a bovine brain cDNA library from which cDNAs corresponding to CKI (CKI-alpha) and two homologous enzymes (CKI-beta and CKI-gamma) were identified. The finding that there are at least four CKI-like enzymes suggests that CKI activity in tissues or cell extracts may be composed of multiple related but distinct protein kinases. This group of enzymes is not similar to any other known protein kinases and may, therefore, represent an additional branch of the protein kinase family.
Rowles
J
J
University of Texas Southwestern Medical Center, Department of Pharmacology, Dallas 75235-9041.
Slaughter
C
C
Moomaw
C
C
Hsu
J
J
Cobb
M H
MH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D047388:Casein Kinases; D002364:Caseins / Q000378:metabolism; D002417:Cattle; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D014176:Protein Biosynthesis; D011494:Protein Kinases / Q000235:genetics* / Q000302:isolation & purification*; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D013950:Thymus Gland / Q000737:chemistry; D014158:Transcription, Genetic
D002364:Caseins; D009841:Oligonucleotides; D012333:RNA, Messenger; D004247:DNA; D011494:Protein Kinases; D047388:Casein Kinases