Identification of three nonessential histidine
kinases in fission yeast. (A) Diagrammatic representation of the domain
architecture of S. pombe (S.p.) Mak1p, Mak2p, and Mak3p
compared with the S. cerevisiae (S.c.) Sln1p and
C. albicans (C.a.) HK1 histidine kinases. The positions
of the following domains are shown in these molecules: putative
serine/threonine kinase domain (diagonally hatched bar), GAF domain
(gray bar), PAS/PAC motifs (open bar), histidine kinase (black bar),
and response-regulator domain (vertically hatched bar). The Mak1p,
Mak2p, and Mak3p sequences appear in the SWISSPROT and EMBL databases
under the accession numbers AL157734, Z98978, and AL031543,
respectively. (B) S. pombe histidine kinases control
cell size at cell division via Mcs4p. Wild-type
(mcs4+) (JM 1059),
mcs4(D412N) (VB1692),
Δmcs4 (JM1468),
Δmak1
Δmak2
Δmak3 (VB1971), or
Δmak1
Δmak2
Δmak3
Δmcs4 (VB1925) cells were grown to log
phase in minimal medium and photographed by using Normarski optics.