Gette, 125 (1993) 235-236 $j 1993 Elsevicr Science Publishers B.V. AL1 rights reserved. 0378-I 119~93~S~6.~ 235

GENE 06984

Sequence of the goat a,,-casein-encoding cDNA*

(Mammary gland; lactoprotein; caprine gene)

Christine Bouniol

Received by G. Bernardi: 24 September 1992; Revised/Accepted: 26 November/30 November 1992; Received at pubfishers: 10 December 1992

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SUMMARY

The complete nucleotide sequence of a caprine ~1,~ -casein-encoding &DNA and the deduced 223-amino-acid sequence of pre-isl,,-casein were determined.

The a,,-casein (cc,,-Cas) is the most phospharylated Cas with up to 13 phosphate groups in bovine species (Brignon et al., 1977). The N- and C-terminal halves of the bovine mature Cas share 40% sequence identity, which suggests that the ancestral gene underwent an

internal duplication (Brignon et al., 1977). The sequences of bovine (Stewart et al., 1987), ovine (Boisnard and Petrissant, 1985), rat (Hobbs and Rosen, 1982), guinea- pig (Hall et al., 1984), mouse (Hennighausen et al., 1982) and pig (Alexander et al., 1992) cl&as cDNAs are

Fig. I. The nt sequence of a cDNA clone encoding the cap&e cx,,-Cas and the deduced aa sequence. A lactating caprine mammary gland cDNA

library constructed in pUCl8 (SmaI site) was probed with an ovine a&as cDNA (Boisnard et Pet&ant, 1985). The positive clones were sequenced

on both strands (Sanger et al., 1977) after subcloning. The nt sequence (upper line) and the deduced 208 aa sequence (lower line) are given. The stop

codon is marked with three asterisks. Similar nt sequence repeats are underlined. Potential phosphorylated aa (Ser, Thr) are underlined with dashed

lines. The putative polyadenylation site is doubly underlined. The 15-aa signal peptide is in bold-face type. GenBank accession No. X65160.

Correspondence to: Dr. C. Houniol, Laboratoire de Genetique Biochimique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas,

France. Tel. (33-l) 34-65-Z-75; Fax (33-I) 34-65-22-73.

*On request. the author will supply detailed experimental evidence for the conclusions reached in this Brief Note.

Abbreviations: aa, amino acid(s); Cas, casein; cDNA, DNA complementary to RNA; nt, nucieotidefs).

236

known. Analysis of an a,,-Cas-encoding clone isolated from a caprine mammary gland cDNA library and 5’ primer extension (6 nt) gave the complete sequence of the 1013 nt aSZ-CasA cDNA (Fig. 1). The 669-nt coding frame, which contains two similar (60%) sequences of 222 nt, is flanked by S- and 3’-untranslated regions of 42 and 302 nt, respectively. This cDNA shares 98.5%, 94.5% and 75.3% similarity with ovine, bovine and porcine a,*-Cas cDNAs but is quite different from its shorter rodent counterparts, in particular that of the mouse (about 700 nt) which lacks the duplicated sequence.

ACKNOWLEDGEMENTS

I thank Dr. C. Leroux for the construction of the cDNA library. Many thanks to C. Printz and J.C. Mercier for valuable discussions and critical reading of the manuscript.

REFERENCES

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