Comparative analysis of proteins induced by heat shock, salinity, and osmotic stress in the nitrogen-fixing cyanobacterium Anabaena sp. strain L-31

Abstract

Heat, salinity, or osmotic stress influenced protein synthesis in nitrogen-fixing Anabaena sp. strain L-31.Salinity and osmotic stresses were identical and specifically induced 15 polypeptides. Four polypeptides were unique to heat shock, and four other polypeptides were induced under every stress. The results demonstrate a commonality and a stress specificity of protein synthesis regulation.Environmental-stress-induced modifications of protein synthesis have been observed in microbes, plants, and animals (3,7,10,(12)(13)(14) Preparation of total-cellular-protein samples, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and two-dimensional electrophoresis (isoelectric focusing followed by SDS-PAGE) were performed as previously described (1,11). Only the reproducible and prominent differences were taken into account.Exposure to heat, salinity, or osmotic stress resulted in alterations in cyanobacterial-protein syntheses (Fig. 1). Three prominent types of modifications were noted: (i) synthesis of several proteins declined, (ii) synthesis of certain other proteins was selectively enhanced, and (iii) synthesis of a new set of proteins was induced de novo. Some of these responses were observed under all stress conditions (tentatively called the common-stress proteins), while others were found to be specific to either heat (heat shock proteins) or salinity/osmotic stress (osmotic-stress proteins).Two-dimensional separation of stress-modulated proteins (Fig. 2) further resolved protein synthesis responses and identified additional polypeptides which could not be visualized by SDS-PAGE (Fig. 1) of 23, 21, 20, 19, 18.5, and 18 kDa) were specifically induced only under salinity/osmotic stress, while induction of 4 proteins (92, 75, 65, and 32 kDa) were restricted to heat shock. The responses of protein synthesis to salt stress and osmotic stress were identical, indicating that the salinity stress-induced proteins previously reported (1) were all a result of osmotic stress per se and that the effect of ionic stress, if any, was negligible. This also explains our earlier observation that the cyanobacterial salinity stress-induced proteins could be induced externally

Regulation and sequence of the Synechococcus sp. strain PCC 7942 groESL operon, encoding a cyanobacterial chaperonin

“…We conclude that these two strains are essentially identical and have only diverged during the time that they have been in laboratory culture. On the other hand, an examination of the published 5 +**KS*V*K********K+LQ*****+*E*****++S****G+**F**SV*N*** 130 W: TI**A***ANPM**A**ALIR*****T**S****TT**C***RE**KL*ILS*TS 109 S: ++*K******HI**T*V++++QA***+*******++******H*VV+***RN*** 108 E: GMNPMDLKRGIDKAVTAAVEELKALSVPCSDSKAIAQVGTISATSDETVGKLIAE 164 Y: *C*****R**SQV**EKV+*F*S*NKKEITT*EE****+****NG*SH****L*S 185 W: *A**VS**K****T*QGLI***ERKARPVKG*GD*KA*AS***GN**LI*AM**D 164 S: *+*AIL********TNF+**QI*SH++++E***S*****A***++*FE**Q+**+ 163 E: AMDKVGKEGVITVEDGTGLQDELDWEGMQFDRGYLSPYFINKPETGAVELESPF 219 Y: **E*********+RE*RT*+***E*T***R****F+*****+D*KS+K**+*K*L 240 W: *I****PD**LSI*SSSSFETTV**E***EI****I**Q*VTNL*KSI**F*NAR 219 S: ***********+L*E*K+MT+**E*T***R**K**+****A+DT*RMEAV+DE** 218 E: ILLADKKISNIREMLPVLEAVAKAGKPLLIIAEDVEGEALATAVVNTIRGIVKVA 274 Y: L**SE****+*QD+**A**ISN+S+R*********D*****ACIL*++**Q***C 295 W: V*IT*Q**TS*K*II*L**QTTQLRC**F*V***IT******L***KL***IN** 274 S: **++****GLVQDLV****+**R**R**V*****+*K*****+***R+**VL+** 273 E: AVKAPGFGDRRKAMLQDIATLTGGTVISEEIGMELEKATLEDLGQAKRWINKDT 329 Y: *********N**NTIG***V******FT**+D+KP*QC*I*N**SCDS++VT*ED 350 W: *I***S**E****V*****IV**AEYLAKDL*LLV*N**VDQ**T*RKIT*HQT* 329 S: ***************E***V****QL*T*+AARK*DTTK*++**K*+*++*T**N 328 E: TTIIDGVGEEAAIQGRVAQIRQQIEEAT-SDYDREKLQERVAKLAGGVAVIKVGA 383 Y: *V*LN*S*PKE***E*IE**+GS*DIT*TNS*EK******L***+******R**G 405 W: **LIADAASKDE**A****LKKELS*-*D*I**S***A**I***S********** 383 S: ***V+E-*N***VK+**D***R****-*E*S**K******L***+*****V**** 381 Y: LAT**+**F**V**G*VD*SG**S*LA***V+++*A*E++**A-**---***P** 564 W: *ES*VI**A****C***N****S*ML**Q-AI*VEK**PKPKVAEP--*E*QLS 542 S: FTA**V**+********+***I*A+++****I*V*K*E-++E+AP*GAG****DF 542 E: MGGMGGMM 548 Y: *P**P*** (14) did not reveal an open reading frame which resembled groES. Thus, the organization of these genes may differ in filamentous and unicellular cyanobacterial strains.…”

“…Heat shock was shown to induce the synthesis of proteins of 92, 75, 65, and 32 kDa by the filamentous cyanobacterium Anabaena sp. strain L-31 (5). The identities of the proteins induced by heat shock of cyanobacteria remain to be determined, as does the nature of the control of their expression.…”

Use of Recombinant Aequorin to Study Calcium Homeostasis and Monitor Calcium Transients in Response to Heat and Cold Shock in Cyanobacteria

“…Ca 2ϩ has been shown to respond to environmental variables in plant cells (Knight et al, 1991a(Knight et al, , 1992(Knight et al, , 1996Chandra and Low, 1997;Takahashi et al, 1997;Gong et al, 1998), and there is increasing evidence that the same might be true for cyanobacteria (Smith, 1995;Norris et al, 1996;Giraldez-Ruiz et al, 1997, 1999. In this context, we were interested in determining whether Ca 2ϩ was involved in signaling of heat and cold shock, because little is known about the initial perception of both environmental stresses in cyanobacteria since most of the studies have dealt with environmental-stress-induced modifications of protein synthesis (Borbely et al, 1985;Nicholson et al, 1987;Bhagwat and Apte, 1989). To study Ca 2ϩ involvement and to elucidate whether the cell response varies according to the specific way of inducing the shock, we applied heat and cold shock in two different ways: (a) cells were placed in cuvettes and immersed in water baths at the appropriate temperature, allowing for continuous heat or cold shock (in this method, cells did not come into contact with hot or cold water); (b) water was injected directly into the sample, resulting in an almost instantaneous change of temperature (in this method, cells came into contact with hot or cold water).…”

Biochemical composition of seven species of cyanobacteria isolated from different aquatic habitats of Western Ghats, Southern India

“…They observed high cell contents of chlorophyll a, carotenoids, proteins and carbohydrates at 100 ppt and in good nutrient conditions. There are certain factors which also influence the protein synthesis (Borbely et al, 1985;Bhagwat and Apte, 1989). Over 300 nitrogen containing metabolites which are lipopeptide in nature have been reported from marine cyanobacteria (Tan, 2007).…”