Identification and characterization of ATPase activity associated with maize (Zea mays) annexins

Abstract

An ATPase activity is associated with maize (Zea mays) annexins. It has a pH optimum of 6.0, shows Michaelis-Menten kinetics and is not stimulated by Ca2+, Mg2+, EDTA or KCl; it is not inhibited by vanadate, molybdate, nitrate or azide, but N-ethylmaleimide inhibits by approximately 30% at 1-2 mM. These properties indicate that the activity is unlike other ATPases, although it has many features in common with the myosin ATPase. Gel filtration shows that the ATPase activity is mainly associated with a 68 kDa protein that is extracted with the p33/p35 annexins and cross-reacts with antibodies to these proteins.

cDNA Isolation and Gene Expression of the Maize Annexins p33 and p35

“…The primary structure is very similar in the type-I1 Ca*+-binding domains of the two annexins (see above), so this may mean that other, lower-affinity sites are important in these annexins; this has proved to be the case for annexin XII (Luecke et al, 1995). An in vivo association of p33 a n d p35 is also a real possibility; we found no evidence in any of our library screens for a cDNA representing the p68 annexin present in coleoptiles (Blackbourn , et al, 1991;McClung et al, 1994) and in root tips (data not shown). The overexpression of the maize annexins is therefore an important goal made more accessible by the work described here because it should allow structure determinations and resolution of questions about Ca2+ binding and a ~3 3 1~3 5 association.…”

“…ATPase activity in maize annexins described by McClung et al (1994) and subsequently confirmed for tomato by Calvert et al (1996). There' are no Walker-type nucleotide binding sites (Walker et al, 1982) in the predicted amino acid sequence, but not a11 nucleotide binding / hydrolyzing proteins have these (Schaap et al, 1994).…”

Annexins of Plant Cells

“…In plant tissues ATPase activity is associated with maize annexins (McClung et al, 1994). The highest levels of activity are found in the fractions in which a 68-kD annexin band is enriched.…”

Immunolocalization of a novel annexin‐like protein encoded by a stress and abscisic acid responsive gene in alfalfa

“…Some of the plant annexins have been shown to possess intrinsic phosphodiesterase activity (Calvert et al, 1996;McClung et al, 1994). Annexins were also suggested to play various roles in secretion and ripening processes (Blackbourn et al, 1992;Clark et al, 1992;Clark and Roux, 1995).…”