A new morphogenesis pathway in bacteria: unbalanced activity of cell wall synthesis machineries leads to coccus-to-rod transition and filamentation in ovococci
A new morphogenesis pathway in bacteria: unbalanced activity of cell wall synthesis machineries leads to coccus-to-rod transition and filamentation in ovococci
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DOI：
10.1111/j.1365-2958.2010.07483.x
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发表时间：
2011-02-01
影响因子：
3.6
通讯作者：
Guedon, Eric
中科院分区：
文献类型：
--
作者：
Perez-Nunez, Daniel;Briandet, Romain;Guedon, Eric
细菌的形状多种多样，具有生物学意义.在大多数真细菌中，细胞形状由细胞壁的坚韧肽聚糖（PG）层（球囊）维持。PG合成机制的组织，由不同的细胞骨架元素编排，决定了球囊的特定形状。在杆状细菌中，肌动蛋白样（MreB）和微管样（FtsZ）细胞骨架分别控制侧壁（伸长）和横壁（分隔）的合成。关于缺乏MreB蛋白的球菌的细胞形态发生知之甚少。虽然球形球菌只显示隔膜生长，但卵球菌还显示周边生长，这是产生其卵形形状的轻微纵向扩张的原因。在这里，我们报告说，卵球菌乳酸乳球菌有能力成为棒状。L.乳酸菌IL 1403野生型细胞在合成培养基中生物膜和无隔生长期间形成长的无隔丝。初生的PG插入和分裂蛋白FtsK定位在多个外周环中，这些环沿花丝沿着有规律地间隔开。我们发现，分离抑制的结果，并在此过程中发挥直接作用，青霉素结合蛋白PBP2x和PBP2b。我们提出了一个L. lactis，并讨论了这种形态分化可能的生物学作用。
P>Bacteria display a variety of shapes, which have biological relevance. In most eubacteria, cell shape is maintained by the tough peptidoglycan (PG) layer of the cell wall, the sacculus. The organization of PG synthesis machineries, orchestrated by different cytoskeletal elements, determines the specific shapes of sacculi. In rod-shaped bacteria, the actin-like (MreB) and the tubuline-like (FtsZ) cytoskeletons control synthesis of the sidewall (elongation) and the crosswall (septation) respectively. Much less is known concerning cell morphogenesis in cocci, which lack MreB proteins. While spherical cocci exclusively display septal growth, ovococci additionally display peripheral growth, which is responsible of the slight longitudinal expansion that generates their ovoid shape. Here, we report that the ovococcus Lactococcus lactis has the ability to become rod-shaped. L. lactis IL1403 wild-type cells form long aseptate filaments during both biofilm and planktonic growth in a synthetic medium. Nascent PG insertion and the division protein FtsK localize in multiple peripheral rings regularly spaced along the filaments. We show that filamentation results from septation inhibition, and that penicillin-binding proteins PBP2x and PBP2b play a direct role in this process. We propose a model for filament formation in L. lactis, and discuss the possible biological role of such morphological differentiation.