Fig. 1. Comparison of the ABD of plectin, dystonin and dystrophin and interaction of plectin with different isoforms of actin. (A) Alignment of the N termini of human plectin (AAB05427), mouse dystonin (P11277) and dystrophin (P11532). Alignment was performed with the CLUSTAL-W program. Black boxes, identical amino acids; gray boxes, amino acid similarity. The bars above the sequence indicate the ABS1, ABS2 and ABS3 sequences. The CH1 and CH2 domains, identified by sequence homology among the ß-spectrin family of proteins, are delineated by dotted boxes. (B) Two-hybrid interaction between the N-terminal part of plectin and different actin isoforms. (Top) Schematic representation of the largest N-terminal construct of plectin (residues 1-339) with its ABD used in this study. (Bottom) Different actin isoforms, -skeletal muscle (-actin), ß-cytoplasmic (ß-actin) and -cytoplasmic (-actin) actin, were used to determine plating efficiency following cotransformation of yeast host strain PJ69-4A with each of the pAS2-plectin subclones listed together with pACT2-actins. Transformation mixtures were spread on SC-LT and SC-LTHA plates and grown at 30°C. Plating efficiency on selective SC-LTHA plates is expressed as a percentage of plating efficiency on non-selective SC-LT plates of the same transformation, thus: ++, >50%; +, 50% (slowly growing colonies); ±, 5-25%; -, 0%. ND, not determined. Plates were scored after 6 and 12 days of growth; slowly growing colonies could only be scored after 12 days of growth. Plating efficiencies of <25% always represented slowly growing colonies. All efficiencies listed represent an average of multiple independent transformations on at least two separate occasions.