Isolation of a high molecular weight actin-binding protein from baby hamster kidney (BHK-21) cells.
A high molecular weight protein (HMWP) with properties similar to those of both actin-binding protein (ABP) and filamin has been isolated from cultured baby hamster kidney (BHK-21) cells. The protein was present in an actomyosin-depleted sucrose extract of the cells and was eluted, upon gel chromatography on Sepharose 4B, near the void volume. The subunit migration on sodium dodecyl sulfate/polyacrylamide gels and the amino acid composition of HMWP were similar to those of ABP and filamin. HMWP bound to and crosslinked F-actin from rabbit muscle, as shown by the formation of a gel that was sedimented with low-speed centrifugation. This interaction was insensitive to temperature and low concentrations of calcium ions, although it may depend on the presence of myosin. Observation of thin sections of the actin-HMWP gel revealed crosslinked complexes of laterally aggregated actin filaments. The axial period of the dense crosslinks was 34 nm. The HMWP may be involved in regulation of microfilament organization.
D000199:Actins / Q000378:metabolism*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002352:Carrier Proteins / Q000032:analysis / Q000302:isolation & purification*; D002460:Cell Line; D006224:Cricetinae; D005782:Gels; D008970:Molecular Weight
D000199:Actins; D000596:Amino Acids; D002352:Carrier Proteins; D005782:Gels