Liverpool group posts contradictory cat sequence
Rohwer group posts cat prion
Lots of UK dogs with TSE -- opinion
Unusual aspects of cat prion -- Alex Bossers
Cat sequences in conflict: alignment
Crocodile prion sequence predicted
2 Oct 97 GenBank Y13698 Taylor,M.S., Newton,D.J., Flanagan,B.F. and Christmas,S.E. Department of Immunology, Liverpool, Merseyside, L69 3GA, UKA 373 bp fragment of cat prion was sequenced by the Liverpool group, corresponding to residues 109-232 in humans or 112-235 in sheep. This is quite sufficient for threading onto mouse and hamster 3D structures. The Liverpool cat sequence shows 8 amino acid differences and 42 nucleotide differences with the Rohwer cat sequence. The sequences show a very low 93% similarity for intra-specific variation so it is impossible that both sequences be correct.
When cat and dog prion amino acid sequences are threaded to refined mouse 3D coordinates, they differ by 0.14 angstroms, rmsd, suggesting that little by way of differential species barrier could exist.
MKHVAGAAAAGAVVGGLGGYMLGSAMSRPLIHFGNDYEDRYYRENMYRYPDQ VYYRPVDQYSNQNNFVRDCVNITVKQRTVTTTTKGENFTETDMKIMERVEQMCVTQYQKESEAYYQRRASA >gi|2463040|gnl|PID|e351514 cat prion MKHVAGAAAAGAVVGGLGGYMLGSAMSRPLIHFGNDYEDRYYRENMYRYPDQVYYRPVDQYSNQNNFVRD CVNITVKQRTVTTTTKGENFTETDMKIMERVVEQMCVTQYQKESEAYYQRRASA >gi|2463039|emb|Y13698|FCPRION Felis catus prion partial, frame 31 ACATGAAGCACGTGGCAGGAGCCGCAGCAGCCGGGGCGGTAGTAGGGGGCCTTGGTGGCTACATGCTGGG GAGTGCCATGAGCAGGCCACTCATTCATTTTGGCAATGACTATGAGGACCGTTACTATCGTGAGAACATG TACCGCTACCCCGACCAAGTATACTACCGGCCAGTGGATCAGTACAGCAACCAGAACAACTTTGTGCGTG ACTGCGTCAACATCACTGTCAAGCAGCGCACAGTGACCACCACCACCAAGGGGGAGAACTTCACAGAGAC CGACATGAAGATCATGGAGCGTGTGGTGGAGCAGATGTGTGTCACCCAGTACCAGAAGGAGTCCGAGGCT TACTACCAAAGAAGGGCGAGCGC
rowher_cat_minimal MKHVAGAAAA GAVVGGLGGY MLGSAMSRPL IHFGNDYEDR YYRENMYRYP liverpool_cat MKHVAGAAAA GAVVGGLGGY MLGSAMSRPL IHFGNDYEDR YYRENMYRYP Consensus MKHVAGAAAA GAVVGGLGGY MLGSAMSRPL IHFGNDYEDR YYRENMYRYP 51 100 rowher_cat_minimal NQVYYRPVDQ YSNQNNFVHD CVNITVKQHT VTTTTKGENF TETDIKIMER liverpool_cat DQVYYRPVDQ YSNQNNFVRD CVNITVKQRT VTTTTKGENF TETDMKIMER Consensus #QVYYRPVDQ YSNQNNFVrD CVNITVKQrT VTTTTKGENF TETDiKIMER 101 124 rowher_cat_minimal VVEQMCITQY QRESEAYYQR GASV liverpool_cat VVEQMCVTQY QKESEAYYQR RASA Consensus VVEQMC!TQY QrESEAYYQR rASa
23 Sept 1997 WebmasterThe cat prion sequence was posted on Sept 22, 1997. My earlier prediction had it right for 205 of the first 206 residues considered. However, at residue alternatives the sequence leaned more towards hooved animals. The other 3 changes were conservative, distal, and previously observed: ile for val, arg for lys, and val for ala.
Still, there were unusual features. In a nutshell, cats looked less like mink-ferret and dog-wolf-dingo and more like horse-zebra, and thus inevitably, more like cow-sheep. This is not be itself impoossible for molecular data in the ferungulates. In the 193 aa aligned, cat scored 97% with bovine and 99% with ovine, 94% to ancestral placental mammal. No bizarre destabilizing mutations occur like those found in White Leghorns and sheep -- cats aren't all that domesticated is the bottom line.
>rowher_cat MVKSHIGSWILVLFVAMWSDVGLCKKRPKPGGGWNTGGSRYPGQ GSPGGNRYPPQGGGGWGQPHGGGWGQPHGGGWGQPHGGGWGQPHGGGGWGQGGSHSQW NKPSKPKTNMKHVAGAAAAGAVVGGLGGYMLGSAMSRPLIHFGNDYEDRYYRENMYRY PNQVYYRPVDQYSNQNNFVHDCVNITVKQHTVTTTTKGENFTETDIKIMERVVEQMCI TQYQRESEAYYQRGASVILFSSPPVILLISFLIFLIVG >gi|2406625|gb|AF003087| Felis catus prion, complete cds ATGGTGAAAAGCCACATAGGCAGCTGGATCCTAGTTCTCTTTGTGGCCATGTGGAGTGACGTTGGCCTCT GCAAGAAGCGACCAAAACCTGGAGGAGGATGGAACACTGGGGGGAGCCGATACCCGGGACAGGGAAGTCC TGGAGGCAACCGCTATCCACCTCAGGGAGGGGGTGGCTGGGGTCAGCCCCATGGAGGTGGCTGGGGCCAA CCTCATGGAGGTGGCTGGGGTCAGCCCCATGGTGGTGGCTGGGGACAGCCACATGGTGGTGGAGGCTGGG GTCAAGGTGGTAGCCACAGTCAGTggaataagcccagtaagccaaaaaccaACATGAAGCATGTGGCAGG AGCTGCTGCAGCTGGAGCAGTGGTAGGGGGCCTTGGTGGCTACATGCTGGGAAGTGCCATGAGCAGGCCT CTTATACATTTTGGCAATGACTATGAGGACCGTTACTATCGTGAAAACATGTACCGTTACCCCAACCAAG TGTACTACAGACCAGTGGATCAGTATAGTAACCAGAACAACTTTGTGCATGACTGTGTCAACATCACAGT CAAGCAACACACAGTCACCACCACCACCAAGGGGGAGAACTTCACCGAAACTGACATCAAGATAATGGAG CGAGTGGTGGAGCAAATGTGCATCACCCAGTACCAGAGAGAATCCGAGGCTTATTACCAAAGAGGGGCAA GTGTgatcctcTTCTCCTCCCCTCCTGTGATCCTCCTCATCTCTTTCCTCATTTTTCTCATAGTAGGATA GGGGCAACCTTCCTGTTTTCATTATThe molecular data is consistent with dogs and cats both at high risk from BSE and scrapie. It seems likely that very large numbers of both dogs and cats must have contracted TSE during the epidemic. 79 cats, or was it 79,000, or 790,000? Dogs could well have a slower course for the disease.
Of course, it would be easy and cheap to do 14-3-3 tests on CSF from some of the tens of thousands of older dogs and cats euthanized each month in London alone. Why speculate on how many dogs or cats got it when it is so easy just to measure? A goodly percentage of older dogs especially, would flunk the test, in my estimation.
But if you don't want to know, you don't ask. The tragedy is that later, as estimating the epidemic in humans becomes a big issue, we will wish all possible measures of species barrier breaching had been made, when it was possible to do them. This opportunity, and many others, is slipping away forever, all so that MAFF doesn't have to take a PR hit on companion animals.
Alex Bossers ... Dutch researcher
Nice work that the cat sequence is posted! Good work and an applause for Rohwers group for posting the sequence immediately! My seq-alerting system gave me a good start this morning.
What 'bothers' me about the cat PrP sequence is that it only differs in 1 amino acid from wildtype-sheep (position 226, E for cat and Q for sheep) and 1 octarepeat plus 7 amino acids from bovine. This would make the hypothesis of BSE passing on to cats less obvious and would suggest that scrapie passing to cats would be more in the picture (based on primary aa comparisons).
Another point that bothers me is that the monoclonal antibody 3F4 reacts with feline prion in immunohistochemistry. The 3F4 monoclonal react very specifically to a region (aa 109-112 of the hamster PrP sequence) containing methionines at aa 109 and 112.
All species so far have these specific methionines (human, hamster, mouse 109M). The cat sequence (3F4+) however does react to 3F4 and one would expect it to have the two metionines also but it doesn't. This would mean that different allelic variants of cat PrP could be present (differing at position 112 V instead of M (hamster numbering) or 115 (cat numbering) and that the sequenced cat allele would be the most uncommen one!??
Liverpool cat has two codons that might consistently distinguish felids from canids, H190R and G232R in sheep numbering. Right now, with one species, they are just 'singlets' of no special significance.
The implication is, if cats got BSE, then dogs probably did too, the sequences being so close, using the Liverpool sequence. The Liverpool cat sequence shows 8 amino acid differences and 42 nucleotide differences with the Rohwer cat sequence -- not possible.
Webmaster 9.24.97Here's the crocodile prion sequence. I would estimate the accuracy to be 99% based on earlier experiences. The method used for weighting sequence characters, low pass fourier filtering in the frequency domain, has been used (unevenly and unknowingly) in phylogeny since the time of Darwin, though no one seems to have realized quite what the rationale for it was.
>earlier_cat_prediction KKRPKPGGGWNTGGSRYPGQGSPGGN RYPPQGGGGWGQPHGGGWGQPHGGGWGQPHGGGWGQPHGGGGWGQGG-SH GQWNKPSKPKTNMKHVAGAAAAGAVVGGLGGYMLGSAMSRPLIHFGNDYE DRYYRENMYRYPNQVYYRPVDQYSNQNNFVHDCVNITVKQHTVTTTTKGE NFTETDIKIMERVVEQMCITQYQRESEAYYQRGASVILFSPPP