The sequence of porcine α_s1‐casein cDNA: evidence for protein variants generated by altered RNA splicing

Abstract

A cDNA library was constructed from mRNA isolated from lactating porcine mammary gland and screened with a bovine asl-casein cDNA clone. Three classes of cDNA isolated varied in the number of bases within the coding region. The full length porcine asl-casein cDN'4 is 1124bp and codes a preprotein of 206 amino acids. The other two classes of a,l-casein cDNA lacked 18 bp and 60 bp respectively when compared to the 1124-bp cDNA sequence. PCR amplification confirmed the presence of these sequences in total RNA. These differences appear to be due to altered RNA splicing.

Biochemical and molecular characterization of polymorphisms of αs1-casein in Sudanese camel (Camelus dromedarius) milk

“…Similarly, missing of exon 4 in bovine CSN1S1*A (Mohr, Koczan, Linder, Hobom, & Erhardt, 1994) and of exon 7 respectively exon 8 in ovine CSN1S1*I respectively CSN1S1*H (Giambra et al, 2010a(Giambra et al, , 2010b, were also reported. Beside exon skipping as a reason for casein alleles as described above, simultaneous occurrence of skipped and non-skipped forms of the same CSN1S1 allele are usual in sheep, goat, cattle, pig, and human (Alexander & Beattie, 1992;Ferranti et al, 1998;Johnsen, Rasmussen, Petersen, & Berglund, 1995;Leroux, Mazure, & Martin, 1992). Within ovine a s1 -CN alleles A, C, and D, for example, the appearance of at least eight protein forms, not related to allelic variability is described (Ferranti et al, 1995;2001;Ferranti, Lilla, Chianese, & Addeo, 1999), whereas 16.9% of whole a s1 -CN is missing exon 16 (Ferranti et al, 1998).…”

The Role of Lactoferrin in Gastrointestinal and Immune Development and Function: A Preclinical Perspective

“…The Role of Lactoferrin in Gastrointestinal and Immune Development and Function: A Preclinical Perspective lactoferrin contains 684 amino acids and shares 71.1% overall amino acid sequence identity with hLF. 74,75 Lactoferrin contains 1-4 glycans at asparagine (Asn) residues 233, 368, 476, and 545, depending on the species. 76 Glycans present in bLF include N-acetyllactosamine, N-acetylglucosamine, galactose, fucose, mannose, and n-acetylneuraminic acid.…”

“…76 Less is known about the glycosylation of porcine lactoferrin, but it appears to have a glycosylation site at Asn472 and possibly Asn365. 74 The N-glycans on hLF are comprised of sialylated and fucosylated complex-type structures, and many contain Lewis(x) epitopes. 77 Barboza et al 78 characterized the glycosylation of hLF in the milk of 5 mothers of the first 10 weeks of lactation by mass spectroscopy.…”