. Author manuscript; available in PMC: 2011 Aug 1.

Published in final edited form as: Hum Mutat. 2010 Aug;31(8):975–982. doi: 10.1002/humu.21301

Table 1.

Comparison of biochemical data obtained in this and previous analyses for Lynch-syndrome-related hMLH1 variants analyzed in this work

Variant ^*	DNA change ^**	Class	Activity		Expr.	Dimerization				This work
Variant ^*	DNA change ^**	Class	DME	MMR activ.	Expr.	Y2H	Co-IP	Affin- ity	PMS2 stabil.	Expr.	PMS2 stabil.	MMR activ.	Class (new)
Gln542Leu	c.1625A>T	VUS	^***¹	^¹ (^⁵)	^***¹	^*² ⁹	^*⁹	^*² ^*³		^***	-	^**	Del
Asn551Thr	c.1652A>C	Del		^***¹	^**¹					^**	n.a.		Del
Leu559Arg	c.1676T>G	Del			- ⁶			- ⁶		^**	n.a.		Del
Ala586Pro	c.1756G>C	VUS	- ¹	^*¹	^**¹					^**	n.a.	^*	Del
Asp601Gly	c.1802A>G	Del								^***	+	^***	VUS
Lys618Ala	c.1852AA>GC	VUS	^*¹	^*¹ ^*⁴	^¹ ^⁴ ^⁶ ^⁷ ^ ⁸	^**²	^***⁴	^² ³ ^**⁶ -⁷	^***⁷	^***	+	^***	VUS
Leu622His	c.1865T>A	Del	- ¹	^***¹	^**¹					^**	n.a.		Del
Leu636Pro	c.1907T>C	VUS								^**	n.a.	^***	Del
Pro648Leu	c.1943C>T	Del	- ¹	^**¹	^*¹ ^ ⁴		^***⁴			^**	n.a.		Del
Pro654Leu	c.1961C>T	Del	- ¹	^¹ ^*⁴	^*¹ ^ ⁴		^***⁴			^**	n.a.		Del
Arg659Leu	c.1976G>T	Del								^**	n.a.		Del
Arg659Pro	c.1976G>C	Del	- ¹	^¹ ^⁴ ^¹⁰	^¹ ^**⁴	^² ^ ⁹	^⁴ ^ ⁹ ^* ¹⁰	^² ^ ³		^*	n.a.		Del
Arg659Gln	c.1976G>A	Neutral	^**¹	^*¹ ^*⁴	^¹ ^*⁴		^***⁴			^**	+	^***	VUS
Thr662Pro	c.1984A>C	VUS	- ¹	^***¹	^**¹					^*	n.a.	^***	Del
Glu663Gly	c.1988A>G	VUS	^***¹	^***¹	^***¹					^***	+	^***	VUS
Leu749Pro	c.2246T>C	Del			^***⁸					^***	-	^**	Del
Tyr750X	c.2250C>A	-			^***⁷				^*⁷	^***	-	^*	Del
Arg755Ser	c.2265G>T	Del	^***¹	- ¹	^***¹					^***	+		Del
Arg755Trp	c.2263A>T	VUS			^***⁷				^***⁷	^**	+	^*	Del

Codon numbering corresponds to the protein sequence of MLH1 (GenBank accession: AAC50285)

^**

Nucleotide numbering reflects cDNA numbering with +1 corresponding to the A of the ATG translation initiation codon in the MLH1 nucleotide sequence (GenBank accession U07343.1)

"Class" – classification of missense mutations according to Chao et al. (Chao, et al., 2008). "Del" – Deleterious, "VUS" – Variant of Uncertain Significance

"DME" – dominant mutator effect of hMLH1 variant interference on yeast MMR (Shimodaira, et al., 1998; Takahashi, et al., 2007). "***" - DME in all three different assays performed (i.e. variant fully functional), "**" - in two, "*" – one, "-" – in none (variant non-functional in MMR)

"MMR activity" – ¹,⁴,¹⁰ in vitro MMR activity: *** corresponds to MMR activity > 60% comparing to wild-type, ** - 30–60%, * - 10–30% - - < 10%, ⁵in vivo activity of equivalent yeast variant

"Expr." – relative expression *** corresponds to >75%, ** - 25–75%, * - <25%

"Dimerization": "Y2H" - yeast-two-hybrid for human homologs; "coIP" - co-immunoprecipitation from insect or human cell extracts; "Affinity" - affinity chromatography using fusion proteins expressed using in vitro transcription-translation systems or in heterologous systems such as E. coli"PMS2 stabil." – MLH1-dependent PMS2 stability in mouse cells or in human cells (this work);

^***

corresponds to > 70% comparing to wild-type, ** - 30–70%, * - 0–30%. n.a. – not applicable, since insufficient levels of MLH1 were present to assess PMS2 stabilization.

References:¹ Takahashi, 2007; ² Kondo, 2003; ³ Guerette, 1999; ⁴ Raevaara, 2005; ⁵ Ellison, 2001; ⁶ Belvedersi, 2006; ⁷Mohd, 2006; ⁸ Perera, 2008; ⁹ Fan, 2007; ¹⁰ Nystrom-Lahti, 2002.