A cell number-counting factor regulates levels of a novel protein, SslA, as part of a group size regulation mechanism in Dictyostelium.

ABSTRACT: Developing Dictyostelium cells form aggregation streams that break into groups of approximately 2 x 10(4) cells. The breakup and subsequent group size are regulated by a secreted multisubunit counting factor (CF). To elucidate how CF regulates group size, we isolated second-site suppressors of smlA(-), a transformant that forms small groups due to oversecretion of CF. smlA(-) sslA1(CR11) cells form roughly wild-type-size groups due to an insertion in the beginning of the coding region of sslA1, one of two highly similar genes encoding a novel protein. The insertion increases levels of SslA. In wild-type cells, the sslA1(CR11) mutation forms abnormally large groups. Reducing SslA levels by antisense causes the formation of smaller groups. The sslA(CR11) mutation does not affect the extracel

SUBMITTER: Gao T 

PROVIDER: S-EPMC2043358 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature