PrionDB: Extraction of mutation data from the literature

2005, PrionDB.

This data was extracted from Medline abstracts and full texts (when available) in an automated manner.

The table below describes the selected point mutation and provides links to other documents. The sentence(s) where the point mutation E199K was found are listed after the table.

The mutated residues are also indicated in the family sequence alignments and hyperlinked to the corresponding mutation pages.

Point mutation E199K in PRIO_MOUSE

Point mutation:	E199K
Cited point mutation:	E199K,E200K
Domain:	Not determined
General numbering (PrionDB):	-
Protein:	PRIO_MOUSE (Prnp,Prn-p)	Swiss-Prot Cross-reference table Family page
Other point mutations / same protein / same position	Point mutations at position 199 in PRIO_MOUSE
Other point mutations / same protein	List of mutations in PRIO_MOUSE
Family alignments	Mammalian prion proteins Prion proteins (PRP, PRNP)
Other point mutations / same position	Position 200 in Mammalian prion proteins family Position 200 in Prion proteins (PRP, PRNP) family
Reference:	Prion proteins carrying pathogenic mutations are resistant to phospholipase cleavage of their glycolipid anchors. Narwa R, Harris DA Biochemistry 1999 Jul 6;38(27):8770-7.	Medline
Other point mutations / same article	List
Text source	HTML full text
Validation status	True positive

Relevant sentences:

E200K

E199K is homologous to a human mutation (E200K) linked to CJD (35 , 36) Mutant PrPs Remain Partially Resistant to PIPLC after Solubilization in Nondenaturing Detergents

E199K

CHO cell lines expressing PG14 , 2 D177N (Met-128) , and E199K moPrPs have been described previously (13 , 14)
Immunoprecipitation was performed as described previously (13) , using antibody P45-66 to recognize D177N and E199K moPrPs , and antibody 3F4 to recognize wild-type and PG14 moPrPs
Results For these studies , we have used stably transfected lines of CHO cells that express either wild-type moPrP or one of three different moPrP mutants: PG14 , D177N , and E199K
E199K is homologous to a human mutation (E200K) linked to CJD (35 , 36) Mutant PrPs Remain Partially Resistant to PIPLC after Solubilization in Nondenaturing Detergents
Interestingly , E199K moPrP , like the wild-type protein , was shifted almost entirely into the aqueous phase
We have previously observed that E199K moPrP is more readily releasable from the surface of biotinylated cells than other mutant moPrPs (50% released , compared to <5% for other mutants ; 14)
Again , E199K moPrP behaves in a manner different from those of the other two mutants , with all of the [3H]palmitate being removed by PIPLC , similar to the result for the wild-type protein
About half of the E199K molecules were released by PIPLC in a hydrophilic form that presumably lacks the GPI anchor , but those that remained on the cell surface were largely (80%) recovered in the detergent phase
In fact , the PG14 and E199K proteins appear to be even more PIPLC-resistant when attached to the cell membrane (Figure 4) than when solubilized in nondenaturing detergents (Figures 2 and 3) , raising the possibility that detergent extraction can modify the properties of the molecules
Moreover , we have noted that the proportion of mutant molecules that escapes cleavage is higher when the phospholipase is applied to intact cells than when it is added to detergent lysates ; this is especially noticeable for E199K PrP , but can be seen for PG14 also (compare Figure 4 to Figures 2 and 3)
E199K moPrP clearly displays biochemical properties that are distinct from those of other mutants
E199K is considerably more PIPLC-releasable , with 50% remaining on the surface after phospholipase treatment compared to >95% for other mutants that have been tested (14)
Interestingly , the E199K molecules that are not released from cells by PIPLC appear to have intact GPI anchors , as assessed by Triton X-114 partitioning (Figure 4 and ref 18)
Taken together , these results suggest that the E199K mutation alters the structure of the PrP molecule in a way that is different from that of some other pathogenic mutations
Consistent with this proposal , recent thermodynamic studies have suggested that some mutations (including D177N) significantly destabilize the structure of the molecule , while others (including E199K) do not (40-42)
Similarly , E199K moPrP is more detergent-soluble than other mutants when expressed in CHO cells (14 , 15)
These results suggest the possibility that E199K is less PIPLC-resistant because it is less aggregated

F.Horn (priondbcmbi.ru.nl), 22-Aug-2005