High impact information on VAR2

• The majority of VAR1 appears to exist as heterocomplexes with VAR2, whereas VAR2 may be present as homocomplexes as well [1].
• Overexpression of AtFtsH1, but not AtFtsH2/VAR2, normalizes the pattern of var1 variegation, restoring a nonvariegated phenotype [2].
• Both mechanisms emphasize compensating activities and the notion of plastid autonomy, but redundant gene products are proposed to play a role in var2, but not in im [3].
• The yellow variegated mutant of Arabidopsis is plastid autonomous and delayed in chloroplast biogenesis [4].
• We suggest that the stochastic pattern of variegation in the mutant may be due to an interplay of factors that regulate var2 gene expression and factors that mediate rates of cell and plastid division [4].

Anatomical context of VAR2

• This finding suggests that VAR1 and VAR2 play a predominant role in the photosystem II repair cycle in thylakoid membranes [1].
• Based on these results, we conclude that VAR1 and VAR2 are the major components of an FtsH complex involved in the repair of photodamaged proteins in thylakoid membranes [1].
• The VAR2 locus has been shown to encode a chloroplastic FtsH, an ATP-dependent protease which is possibly involved in the degradation of thylakoid proteins and plastid development [5].

Other interactions of VAR2

• These observations led us to examine whether VAR1 and VAR2 form a complex [1].

References